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121-570: A selection of songs from Folk Den, with guest vocalists, was released on CD as Treasures from the Folk Den , which was nominated for a Grammy Award in 2002 for Best Traditional Folk Album. In November 2005, McGuinn released a four-CD box set containing one hundred of his favorite songs from the Folk Den. This music magazine or journal–related article is a stub . You can help Misplaced Pages by expanding it . See tips for writing articles about magazines . Further suggestions might be found on

242-494: A Red Book CD; thus, the mono source material is usually presented as two identical channels in a standard Red Book stereo track (i.e., mirrored mono ); an MP3 CD , can have audio file formats with mono sound. CD-Text is an extension of the Red Book specification for an audio CD that allows for the storage of additional text information (e.g., album name, song name, artist) on a standards-compliant audio CD. The information

363-437: A personal computer hard disk drive . Several other formats were further derived, both pre-pressed and blank user writable, including write-once audio and data storage ( CD-R ), rewritable media ( CD-RW ), Video CD (VCD), Super Video CD (SVCD), Photo CD , Picture CD , Compact Disc-Interactive ( CD-i ), Enhanced Music CD , and Super Audio CD (SACD) which may have a CD-DA layer. The optophone , first presented in 1931,

484-450: A 1. A Red Book -compatible CD-R has pit-and-land-shaped spots on a layer of organic dye instead of actual pits and lands; a laser creates the spots by altering the reflective properties of the dye. Due to the weaker error correction sector structure used on audio CDs and video CDs ( Mode 2 Form 2 ) than on data discs ( Mode 1 or Mode 2 Form 1 ), C2 errors are not correctable and signify data loss. Even with uncorrectable errors,

605-474: A 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, and cross-interleaved Reed-Solomon coding (CIRC) error correction code —specifications similar to those later 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

726-419: A 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, and cross-interleaved Reed-Solomon coding (CIRC) error correction code —specifications similar to those later 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

847-433: A CD is called a track . A CD can contain up to 99 tracks (including a data track for mixed mode discs ). Each track can in turn have up to 100 indexes, though players which still support this feature have become rarer over time. The vast majority of songs are recorded under index 1, with the pregap being index 0. Sometimes hidden tracks are placed at the end of the last track of the disc, often using index 2 or 3, or using

968-466: A CD-DA consists of two-channel signed 16- bit LPCM sampled at 44,100 Hz and written as a little-endian interleaved stream with left channel coming first. The sampling rate is adapted from that attained when recording digital audio on videotape with a PCM adaptor , an earlier way of storing digital audio. An audio CD can represent frequencies up to 22.05 kHz, the Nyquist frequency of

1089-603: A CD. VCDs are playable in dedicated VCD players, most modern DVD-Video players, personal computers, and some video game consoles. The VCD standard was created in 1993 by Sony, Philips, Matsushita , and JVC and is referred to as the White Book standard. Overall picture quality is intended to be comparable to VHS video. Poorly compressed VCD video can sometimes be of lower quality than VHS video, but VCD exhibits block artifacts rather than analog noise and does not deteriorate further with each use. 352×240 (or SIF ) resolution

1210-467: A binary flag in the disc subcode instructs the player to apply de-emphasis filtering if appropriate. Playback of such discs in a computer or ripping to WAV files typically does not take into account the pre-emphasis, so such files play back with an incorrect frequency response. FFmpeg has a filter to remove (or apply) the pre-emphasis in order to create standard WAV files, or to create CDs with pre-emphasis. Four-channel, or quadraphonic , supported

1331-464: A block of 588 pairs of left and right audio samples. Timecode contained in the subchannel data allows the reading device to locate the region of the disc that corresponds to the timecode in the TOC. The TOC on discs is analogous to the partition table on hard drives . Nonstandard or corrupted TOC records are abused as a form of CD/DVD copy protection , in e.g. the key2Audio scheme. The largest entity on

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1452-499: A compact disc player uses error concealment with the aim of making the damage unhearable. The audio data stream in an audio CD is continuous but has three parts. The main portion, further divided into playable audio tracks, is the program area . This section is preceded by a lead-in track and followed by a lead-out track. The lead-in and lead-out tracks encode only silent audio, but all three sections contain subcode data streams. The lead-in's subcode contains repeated copies of

1573-412: A diameter of 115 mm. Sony did not yet have such a facility. If Sony had agreed on the 115-mm disc, Philips would have had a significant competitive edge in the market. The long playing time of Beethoven's Ninth Symphony imposed by Ohga was used to push Philips to accept 120 mm, so that Philips' PolyGram lost its edge on disc fabrication. The 74-minute playing time of a CD, which is longer than

1694-419: A diameter of 120 mm (4.7 in), and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650   MiB ( 681,574,400  bytes) of data. Capacity is routinely extended to 80 minutes and 700  MiB ( 734,003,200  bytes), 90 minutes 800  MiB ( 838,860,800  bytes), or 99 minutes 870  MiB ( 912,261,120  bytes) by arranging data more closely on

1815-479: A diameter of 20 cm (7.9 in) 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 then 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 (4.5 in),

1936-427: A diameter of 20 cm (7.9 in) 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 then 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 (4.5 in),

2057-417: A disc played from beginning to end slows its rotation rate during playback. The program area is 86.05 cm and the length of the recordable spiral is 86.05 cm / 1.6 μm = 5.38 km. With a scanning speed of 1.2 m/s, the playing time is 74 minutes or 650 MiB of data on a CD-ROM. A disc with data packed slightly more densely is tolerated by most players (though some old ones fail). Using

2178-400: A former member of the task force, gives background information on the many technical decisions made, including the choice of the sampling frequency, playing time, and disc diameter. The task force consisted of around 6 persons, though according to Philips, the compact disc was "invented collectively by a large group of people working as a team". Early milestones in the launch and adoption of

2299-400: A former member of the task force, gives background information on the many technical decisions made, including the choice of the sampling frequency, playing time, and disc diameter. The task force consisted of around 6 persons, though according to Philips, the compact disc was "invented collectively by a large group of people working as a team". Early milestones in the launch and adoption of

2420-469: A graphics signal (typically, the CD+G player is hooked up to a television set or a computer monitor); these graphics are almost exclusively used to display lyrics on a television set for karaoke performers to sing along with. The CD+G format takes advantage of the channels R through W. These six bits store the graphics information. CD + Extended Graphics (CD+EG, also known as CD+XG) is an improved variant of

2541-662: 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 extremely 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, and, by 1992, CD sales surpassed those of prerecorded music-cassette tapes. The success of

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2662-563: 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 standard was formally adopted by the IEC as an international standard in 1987, with various amendments becoming part of

2783-452: 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 standard was formally adopted by the IEC as an international standard in 1987, with various amendments becoming part of

2904-453: A linear velocity of 1.2 m/s and a narrower track pitch of 1.5 μm increases the playing time to 80 minutes, and data capacity to 700 MiB. Even denser tracks are possible, with semi-standard 90 minute/800 MiB discs having 1.33 μm, and 99 minute/870 MiB having 1.26 μm, but compatibility suffers as density increases. A CD is read by focusing a 780 nm wavelength ( near infrared ) semiconductor laser through

3025-476: A malfunctioning CD writer . Error scanning can reliably predict data losses caused by media deterioration. Support of error scanning differs between vendors and models of optical disc drives , and extended error scanning (known as "advanced error scanning" in Nero DiscSpeed ) has only been available on Plextor and some BenQ optical drives so far, as of 2020. The digital data on a CD begins at

3146-495: 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 extremely 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, and, by 1992, CD sales surpassed those of prerecorded music-cassette tapes. The success of

3267-488: A second of audio: 588 pairs of left and right samples. This timecode frame is distinct from the 33-byte channel-data frame described above, and is used for time display and positioning the reading laser. When editing and extracting CD audio, this timecode frame is the smallest addressable time interval for an audio CD; thus, track boundaries only occur on these frame boundaries. Each of these structures contains 98 channel-data frames, totaling 98 × 24 = 2,352 bytes of music. The CD

3388-460: A variation of this technique called pulse-density modulation (PDM), while Matsushita (now Panasonic ) chose pulse-width modulation (PWM), advertising it as MASH, which is an acronym derived from their patented Multi-stAge noiSe-sHaping PWM topology. The CD was primarily planned as the successor to the vinyl record for playing music, rather than as a data storage medium. However, CDs have grown to encompass other applications. In 1983, following

3509-460: A variation of this technique called pulse-density modulation (PDM), while Matsushita (now Panasonic ) chose pulse-width modulation (PWM), advertising it as MASH, which is an acronym derived from their patented Multi-stAge noiSe-sHaping PWM topology. The CD was primarily planned as the successor to the vinyl record for playing music, rather than as a data storage medium. However, CDs have grown to encompass other applications. In 1983, following

3630-518: A way to produce 16-bit quality using its 14-bit DAC by using four times oversampling . Some early CDs were mastered with pre-emphasis , an artificial boost of high audio frequencies. The pre-emphasis improves the apparent signal-to-noise ratio by making better use of the channel's dynamic range. On playback, the player applies a de-emphasis filter to restore the frequency response curve to an overall flat one. Pre-emphasis time constants are 50 μs and 15 μs (9.49 dB boost at 20 kHz), and

3751-451: A worm gear is used, a second shorter-throw linear motor, in the form of a coil and magnet, makes fine position adjustments to track eccentricities in the disk at high speed. Some CD drives (particularly those manufactured by Philips during the 1980s and early 1990s) use a swing arm similar to that seen on a gramophone. The pits and lands do not directly represent the 0s and 1s of binary data . Instead, non-return-to-zero, inverted encoding

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3872-453: Is added to the beginning of each frame to assist with synchronization, so the reading device can locate frames easily. With this, a frame ends up containing 588 bits of channel data which are decoded to 192 bits of digital audio. The frames of channel data are finally written to disc physically in the form of pits and lands , with each pit or land representing a series of zeroes, and with the transition points—the edge of each pit—representing

3993-407: Is debatable whether Russell's concepts, patents, and prototypes instigated and in some measure influenced the compact disc's design. 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. Unlike the prior art by Optophonie and James Russell, the information on the disc

4114-506: Is described in a document produced in 1980 by the format's joint creators, Sony and Philips. The document is known colloquially as the Red Book CD-DA after the color of its cover. The format is a two-channel 16-bit PCM encoding at a 44.1 kHz sampling rate per channel. Four-channel sound was to be an allowable option within the Red Book format, but has never been implemented. Monaural audio has no existing standard on

4235-411: Is divided into frames, containing twelve samples each (six left and six right samples, alternating), for a total of 192 bits (24 bytes) of audio data per frame. This stream of audio frames is then subjected to CIRC encoding, which segments and rearranges the data and expands it with error correction codes in a way that allows occasional read errors to be detected and corrected. CIRC encoding interleaves

4356-407: Is playable in standard CD players, thus making them backward compatible. CD- MIDI is a format used to store music-performance data, which upon playback is performed by electronic instruments that synthesize the audio. Hence, unlike the original Red Book CD-DA, these recordings are not digitally sampled audio recordings. The CD-MIDI format is defined as an extension of the original Red Book . For

4477-510: Is protected by a film of lacquer normally spin coated directly on the reflective layer. The label is printed on the lacquer layer, usually by screen printing or offset printing . CD data is represented as tiny indentations known as pits , encoded in a spiral track molded into the top of the polycarbonate layer. The areas between pits are known as lands . Each pit is approximately 100  nm deep by 500 nm wide, and varies from 850 nm to 3.5  μm in length. The distance between

4598-522: Is read from a reflective layer using a laser as a light source through a protective substrate. Prototypes were developed by Philips and Sony independently in the late 1970s. Although originally 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

4719-432: Is stored either in the lead-in area of the CD, where there are roughly five kilobytes of space available or in the subcode channels R to W on the disc, which can store about 31 megabytes. Compact Disc + Graphics is a special audio compact disc that contains graphics data in addition to the audio data on the disc. The disc can be played on a regular audio CD player, but when played on a special CD+G player, it can output

4840-499: Is the standard format for audio compact discs . The standard is defined in the Red Book technical specifications , which is why the format is also dubbed "Redbook audio" in some contexts. CDDA utilizes pulse-code modulation (PCM) and uses a 44,100 Hz sampling frequency and 16-bit resolution, and was originally specified to store up to 74 minutes of stereo audio per disc. The first commercially available audio CD player ,

4961-408: Is used: a change from either pit to land or land to pit indicates a 1, while no change indicates a series of 0s. There must be at least two, and no more than ten 0s between each 1, which is defined by the length of the pit. This, in turn, is decoded by reversing the eight-to-fourteen modulation used in mastering the disc, and then reversing the cross-interleaved Reed–Solomon coding , finally revealing

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5082-570: The 44.1 kHz sample rate. There was a long debate over the use of 16-bit (Sony) or 14-bit (Philips) quantization , and 44,056 or 44,100 samples/s (Sony) or approximately 44,000 samples/s (Philips). When the Sony/Philips task force designed the Compact Disc, Philips had already developed a 14-bit D/A converter (DAC), but Sony insisted on 16-bit. In the end Sony won, so 16 bits and 44.1 kilosamples per second prevailed. Philips found

5203-483: The Compact Disc + Graphics (CD+G) format. Like CD+G, CD+EG uses basic CD-ROM features to display text and video information in addition to the music being played. This extra data is stored in subcode channels R-W. Very few CD+EG discs have been published. Super Audio CD (SACD) is a high-resolution, read-only optical audio disc format that was designed to provide higher-fidelity digital audio reproduction than

5324-661: The Compact Disc Digital Audio format which typically provides 74 minutes of audio on a disc. In later years, the compact disc was adapted for non-audio computer data storage purposes as CD-ROM and its derivatives. First released in Japan in October 1982, the CD was the second optical disc technology to be invented, after the much larger LaserDisc (LD). By 2007, 200 billion CDs (including audio CDs, CD-ROMs and CD-Rs) had been sold worldwide. Standard CDs have

5445-522: The Red Book . Introduced in 1999, it was developed by Sony and Philips, the same companies that created the Red Book . SACD was in a format war with DVD-Audio , but neither has replaced audio CDs. The SACD standard is referred to as the Scarlet Book standard. Titles in the SACD format can be issued as hybrid discs; these discs contain the SACD audio stream as well as a standard audio CD layer which

5566-563: The Sony CDP-101 , was released in October 1982 in Japan. The format gained worldwide acceptance in 1983–84, selling more than a million CD players in its first two years, to play 22.5 million discs, before overtaking records and cassette tapes to become the dominant standard for commercial music. Peaking around year 2000, the audio CD contracted over the next decade due to rising popularity and revenue from digital downloading , and during

5687-471: The Sound Blaster 16 . The optophone , first presented in 1931, was an early device that used light for both recording and playback of sound signals on a transparent photograph . More than thirty years later, American inventor James T. Russell has been credited with inventing the first system to record digital media on a photosensitive plate. Russell's patent application was filed in 1966, and he

5808-752: The vinyl revival . During the 2010s, the increasing popularity of solid-state media and music streaming services caused automakers to remove automotive CD players in favor of minijack auxiliary inputs, wired connections to USB devices and wireless Bluetooth connections. Automakers viewed CD players as using up valuable space and taking up weight which could be reallocated to more popular features, like large touchscreens. By 2021, only Lexus and General Motors were still including CD players as standard equipment with certain vehicles. CDs continued to be strong in some markets such as Japan where 132 million units were produced in 2019. The decline in CD sales has slowed in recent years; in 2021, CD sales increased in

5929-752: The vinyl revival . During the 2010s, the increasing popularity of solid-state media and music streaming services caused automakers to remove automotive CD players in favor of minijack auxiliary inputs, wired connections to USB devices and wireless Bluetooth connections. Automakers viewed CD players as using up valuable space and taking up weight which could be reallocated to more popular features, like large touchscreens. By 2021, only Lexus and General Motors were still including CD players as standard equipment with certain vehicles. CDs continued to be strong in some markets such as Japan where 132 million units were produced in 2019. The decline in CD sales has slowed in recent years; in 2021, CD sales increased in

6050-716: The 120 mm size was adopted. The adoption of EFM in June 1980 allowed 30 percent more playing time that would have resulted in 97 minutes for 120 mm diameter or 74 minutes for a disc as small as 100 millimetres (3.9 in). Instead, the information density was lowered by 30 percent to keep the playing time at 74 minutes. The 120 mm diameter has been adopted by subsequent formats, including Super Audio CD , DVD , HD DVD , and Blu-ray Disc. The 80-millimetre (3.1 in) diameter discs (" Mini CDs ") can hold up to 24 minutes of music or 210 MiB. The logical format of an audio CD (officially Compact Disc Digital Audio or CD-DA)

6171-611: The 2000s designed as successors to the CD: the Super Audio CD (SACD) and DVD-Audio . However neither of these were adopted partly due to increased relevance of digital (virtual) music and the apparent lack of audible improvements in audio quality to most human ears. These effectively extended the CD's longevity in the music market. With the advent and popularity of Internet-based distribution of files in lossy-compressed audio formats such as MP3 , sales of CDs began to decline in

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6292-500: The 2000s designed as successors to the CD: the Super Audio CD (SACD) and DVD-Audio . However neither of these were adopted partly due to increased relevance of digital (virtual) music and the apparent lack of audible improvements in audio quality to most human ears. These effectively extended the CD's longevity in the music market. With the advent and popularity of Internet-based distribution of files in lossy-compressed audio formats such as MP3 , sales of CDs began to decline in

6413-502: The 2000s. For example, between 2000 and 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%. Despite rapidly declining sales year-over-year, the pervasiveness of the technology lingered for a time, with companies placing CDs in pharmacies, supermarkets, and filling station convenience stores to target buyers less likely to be able to use Internet-based distribution. In 2012, CDs and DVDs made up only 34% of music sales in

6534-502: The 2000s. For example, between 2000 and 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%. Despite rapidly declining sales year-over-year, the pervasiveness of the technology lingered for a time, with companies placing CDs in pharmacies, supermarkets, and filling station convenience stores to target buyers less likely to be able to use Internet-based distribution. In 2012, CDs and DVDs made up only 34% of music sales in

6655-465: The 2010s by digital music streaming , but has remained as one of the primary distribution methods for the music industry . In the United States, phonograph record revenues surpassed the CD in 2020 for the first time since the 1980s, but in other major markets like Japan it remains the premier music format by a distance and in Germany it outsold other physical formats at least fourfold in 2022. In

6776-403: The 22 minutes per side typical of long-playing (LP) vinyl albums , was often used to the CD's advantage during the early years when CDs and LPs vied for commercial sales. CDs would often be released with one or more bonus tracks , enticing consumers to buy the CD for the extra material. However, attempts to combine double LPs onto one CD occasionally resulted in the opposite situation in which

6897-508: The CD originally aimed at a playing time of 60 minutes with a disc diameter of 100 mm (Sony) or 115 mm (Philips). Sony vice-president Norio Ohga suggested extending the capacity to 74 minutes to accommodate the recording of Wilhelm Furtwängler conducting Ludwig van Beethoven 's Ninth Symphony at the 1951 Bayreuth Festival . The additional 14-minute playing time required increasing disc diameter. Kees Schouhamer Immink , Philips' chief engineer, however, denies this, claiming that

7018-663: The CD would instead offer less audio than the LP. One such example was with DJ Jazzy Jeff & The Fresh Prince 's double album He's the DJ, I'm the Rapper , in which initial CD releases of the album had multiple tracks edited down for length to fit on a single disc; recent CD reissues package the album across two discs as a result. The emergence of 80-minute CDs allowed for some double albums that were previously edited for length, e.g. 1999 by Prince , or packaged as double CDs, e.g. Tommy by

7139-467: The CD's introduction, Immink and Joseph Braat presented the first experiments with erasable compact discs during the 73rd AES Convention . In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, recordable CD-R discs were introduced. Recordable CDs became an alternative to tape for recording and distributing music and could be duplicated without degradation in sound quality. Other newer video formats such as DVD and Blu-ray use

7260-467: The CD's introduction, Immink and Joseph Braat presented the first experiments with erasable compact discs during the 73rd AES Convention . In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, recordable CD-R discs were introduced. Recordable CDs became an alternative to tape for recording and distributing music and could be duplicated without degradation in sound quality. Other newer video formats such as DVD and Blu-ray use

7381-444: The CD, the optical parameters, deviations and error rate, modulation system ( eight-to-fourteen modulation , EFM) and error correction facility (CIRC), and the eight subcode channels . These parameters are common to all compact discs and used by all logical formats: audio CD, CD-ROM , etc. The standard also specifies the form of digital audio encoding. The first edition of the Red Book was released in 1980 by Philips and Sony; it

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7502-632: The CD. CIRC encoding plus the subcode byte generates 33-byte long frames, called channel-data frames. These frames are then modulated through eight-to-fourteen modulation (EFM), where each 8-bit byte is replaced with a corresponding 14-bit word designed to reduce the number of transitions between 0 and 1. This reduces the density of physical pits on the disc and provides an additional degree of error tolerance. Three merging bits are added before each 14-bit word for disambiguation and synchronization. In total, there are 33 × (14 + 3) = 561 bits. A 27-bit word (a 24-bit pattern plus 3 merging bits)

7623-475: The DAC. Even when using high-precision components, this approach was prone to decoding errors. Another issue was jitter , a time-related defect. Confronted with the instability of DACs, manufacturers initially turned to increasing the number of bits in the DAC and using several DACs per audio channel, averaging their output. This increased the cost of CD players but did not solve the core problem. A breakthrough in

7744-426: The DAC. Even when using high-precision components, this approach was prone to decoding errors. Another issue was jitter , a time-related defect. Confronted with the instability of DACs, manufacturers initially turned to increasing the number of bits in the DAC and using several DACs per audio channel, averaging their output. This increased the cost of CD players but did not solve the core problem. A breakthrough in

7865-451: The US for the first time since 2004, with Axios citing its rise to "young people who are finding they like hard copies of music in the digital age". It came at the same time as both vinyl and cassette reached sales levels not seen in 30 years. The RIAA reported that CD revenue made a dip in 2022, before increasing again in 2023 and overtook downloading for the first time in over a decade. In

7986-403: The US for the first time since 2004, with Axios citing its rise to "young people who are finding they like hard copies of music in the digital age". It came at the same time as both vinyl and cassette reached sales levels not seen in 30 years. The RIAA reported that CD revenue made a dip in 2022, before increasing again in 2023 and overtook downloading for the first time in over a decade. In

8107-521: The US, 33.4 million CD albums were sold in the year 2022. In France in 2023, 10.5 million CDs were sold, almost double that of vinyl, but both of them represented generated 12% each of the French music industry revenues. Sony and Philips received praise for the development of the compact disc from professional organizations. These awards include: A CD is made from 1.2-millimetre (0.047 in) thick, polycarbonate plastic, and weighs 14–33 grams. From

8228-424: The US, 33.4 million CD albums were sold in the year 2022. In France in 2023, 10.5 million CDs were sold, almost double that of vinyl, but both of them represented generated 12% each of the French music industry revenues. Sony and Philips received praise for the development of the compact disc from professional organizations. These awards include: The Red Book specifies the physical parameters and properties of

8349-620: The United States. By 2015, only 24% of music in the United States was purchased on physical media, two thirds of this consisting of CDs; however, in the same year in Japan, over 80% of music was bought on CDs and other physical formats. In 2018, U.S. CD sales were 52 million units—less than 6% of the peak sales volume in 2000. In the UK, 32 million units were sold, almost 100 million fewer than in 2008. In 2018, Best Buy announced plans to decrease their focus on CD sales, however, while continuing to sell records, sales of which are growing during

8470-572: The United States. By 2015, only 24% of music in the United States was purchased on physical media, two thirds of this consisting of CDs; however, in the same year in Japan, over 80% of music was bought on CDs and other physical formats. In 2018, U.S. CD sales were 52 million units—less than 6% of the peak sales volume in 2000. In the UK, 32 million units were sold, almost 100 million fewer than in 2008. In 2018, Best Buy announced plans to decrease their focus on CD sales, however, while continuing to sell records, sales of which are growing during

8591-526: The Who , to be re-released on a single disc. Playing times beyond 74 minutes are achieved by decreasing track pitch (the distance separating the track as it spirals the disc). However, most players can still accommodate the more closely spaced data if it is still within Red Book tolerances. Manufacturing processes used in the final years of CD technology allowed an audio CD to contain up to 98 minutes (variable from one replication plant to another) without requiring

8712-443: The article's talk page . This online magazine–related article is a stub . You can help Misplaced Pages by expanding it . See tips for writing articles about magazines . Further suggestions might be found on the article's talk page . Compact disc The compact disc ( CD ) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. It uses

8833-527: The audio (two bytes × two channels × six samples = 24 bytes), eight CIRC error-correction bytes, and one subcode byte. As described in the "Data encoding" section, after the EFM modulation the number of bits in a frame totals 588. On a Red Book audio CD, data is addressed using the MSF scheme , with timecodes expressed in minutes, seconds and another type of frames (mm:ss:ff), where one frame corresponds to 1/75 of

8954-445: The audio frames throughout the disc over several consecutive frames so that the information will be more resistant to burst errors . Therefore, a physical frame on the disc will actually contain information from multiple logical audio frames. This process adds 64 bits of error correction codes to each frame. After this, 8 bits of subcode data are added to each of these encoded frames, which is used for control and addressing when playing

9075-406: The bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. Because the pits are indented into the top layer of the disc and are read through the transparent polycarbonate base, the pits form bumps when read. The laser hits the disc, casting a circle of light wider than the modulated spiral track reflecting partially from

9196-451: The center of the disc and proceeds toward the edge, which allows adaptation to the different sizes available. Standard CDs are available in two sizes. By far, the most common is 120 millimetres (4.7 in) in diameter, with a 74-, 80, 90, or 99-minute audio capacity and a 650, 700, 800, or 870 MiB (737,280,000-byte) data capacity. Discs are 1.2 millimetres (0.047 in) thick, with a 15 millimetres (0.59 in) center hole. The size of

9317-407: The center outward, components are: the center spindle hole (15 mm), the first-transition area (clamping ring), the clamping area (stacking ring), the second-transition area (mirror band), the program (data) area, and the rim. The inner program area occupies a radius from 25 to 58 mm. A thin layer of aluminum or, more rarely, gold is applied to the surface, making it reflective. The metal

9438-450: 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 and 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 to develop an analog optical audio disc with

9559-450: 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 and 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 to develop an analog optical audio disc with

9680-419: The content creator to sign a waiver releasing the plant owner from responsibility if the CD produced is marginally or entirely unreadable by some playback equipment. In this final practice, maximum CD playing time crept higher by reducing minimum engineering tolerances. Each audio sample is a signed 16-bit two's complement integer , which has sample values ranging from −32768 to +32767. The source audio data

9801-423: 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. In 1973, his team developed a digital PCM adaptor that made audio recordings using a Betamax video recorder. After this, in 1974 the leap to storing digital audio on an optical disc

9922-423: 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. In 1973, his team developed a digital PCM adaptor that made audio recordings using a Betamax video recorder. After this, in 1974 the leap to storing digital audio on an optical disc

10043-480: The disc's table of contents (TOC), which provides an index of the start positions of the tracks in the program area and of the lead-out. The track positions are referenced by absolute timecode , relative to the start of the program area, in MSF format: minutes, seconds, and fractional seconds called frames . Each timecode frame is one seventy-fifth of a second, and corresponds to a block of 98 channel-data frames—ultimately,

10164-406: The entire market share in regard to US music sales . The CD is considered the last dominant audio format of the album era , as the rise of MP3 , iTunes , cellular ringtones , and other downloadable music formats in the mid-2000s ended the decade-long dominance of the CD. The format was later adapted (as CD-ROM ) for general purpose data storage and initially could hold much more data than

10285-516: The first few years of its existence, the CD was a medium used purely for audio. In 1988, the Yellow Book CD-ROM standard was established by Sony and Philips, which defined a non-volatile optical data computer data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive. Video CD (VCD, View CD, and Compact Disc digital video) is a standard digital format for storing video media on

10406-463: The first four UK albums by the Beatles were released in mono on compact disc. The growing acceptance of the CD in 1983 marks the beginning of the popular digital audio revolution. It was enthusiastically received, especially in the early-adopting classical music and audiophile communities, and its handling quality received particular praise. As the price of players gradually came down, and with

10527-408: The first four UK albums by the Beatles were released in mono on compact disc. The growing acceptance of the CD in 1983 marks the beginning of the popular digital audio revolution. It was enthusiastically received, especially in the early-adopting classical music and audiophile communities, and its handling quality received particular praise. As the price of players gradually came down, and with

10648-813: The format included: The first artist to sell a million copies on CD was Dire Straits , with their 1985 album Brothers in Arms . One of the first CD markets was devoted to reissuing popular music whose commercial potential was already proven. The first major artist to have their entire catalog converted to CD was David Bowie , whose first fourteen studio albums (up to Scary Monsters (and Super Creeps) ) of (then) sixteen were made available by RCA Records in February 1985, along with four greatest hits albums; his fifteenth and sixteenth albums ( Let's Dance and Tonight , respectively) had already been issued on CD by EMI Records in 1983 and 1984, respectively. On 26 February 1987,

10769-706: The format included: The first artist to sell a million copies on CD was Dire Straits , with their 1985 album Brothers in Arms . One of the first CD markets was devoted to reissuing popular music whose commercial potential was already proven. The first major artist to have their entire catalog converted to CD was David Bowie , whose first fourteen studio albums (up to Scary Monsters (and Super Creeps) ) of (then) sixteen were made available by RCA Records in February 1985, along with four greatest hits albums; his fifteenth and sixteenth albums ( Let's Dance and Tonight , respectively) had already been issued on CD by EMI Records in 1983 and 1984, respectively. On 26 February 1987,

10890-530: The hole was chosen by Joop Sinjou and based on a Dutch 10-cent coin: a dubbeltje . Philips/Sony patented the physical dimensions. The official Philips history says the capacity was specified by Sony executive Norio Ohga to be able to contain the entirety of Beethoven's Ninth Symphony on one disc. This is a myth according to Kees Immink , as the EFM code format had not yet been decided in December 1979, when

11011-576: The increase was motivated by technical considerations and that even after the increase in size, the Furtwängler recording would not have fit onto one of the earliest CDs. According to a Sunday Tribune interview, the story is slightly more involved. In 1979, Philips owned PolyGram , one of the world's largest music distributors. PolyGram had set up a large experimental CD plant in Hannover , Germany, which could produce huge numbers of CDs having

11132-565: The information for extensions that is available in the Red Book , such as the details for CD-Text , CD+G and CD+EG . The standard is not freely available and must be licensed. It is available from Philips and the IEC. As of 2013 , Philips outsources licensing of the standard to Adminius , which charges US$ 100 for the Red Book , plus US$ 50 each for the Subcode Channels R-W and CD Text Mode annexes. The audio contained in

11253-505: The introduction of the portable Discman , the CD began to gain popularity in the larger popular and rock music markets. With the rise in CD sales, pre-recorded cassette tape sales began to decline in the late 1980s; CD sales overtook cassette sales in the early 1990s. In 1988, 400 million CDs were manufactured by 50 pressing plants around the world. Early CD players employed binary-weighted digital-to-analog converters (DAC), which contained individual electrical components for each bit of

11374-505: The introduction of the portable Discman , the CD began to gain popularity in the larger popular and rock music markets. With the rise in CD sales, pre-recorded cassette tape sales began to decline in the late 1980s; CD sales overtook cassette sales in the early 1990s. In 1988, 400 million CDs were manufactured by 50 pressing plants around the world. Early CD players employed binary-weighted digital-to-analog converters (DAC), which contained individual electrical components for each bit of

11495-476: The label side of the disc. Scratches on the clear side can be repaired by refilling them with similar refractive plastic or by careful polishing. The edges of CDs are sometimes incompletely sealed, allowing gases and liquids to enter the CD and corrode the metal reflective layer and/or interfere with the focus of the laser on the pits, a condition known as disc rot . The fungus Geotrichum candidum has been found—under conditions of high heat and humidity—to consume

11616-510: The lands and partially from the top of any bumps where they are present. As the laser passes over a pit (bump), its height means that the round trip path of the light reflected from its peak is 1/2 wavelength out of phase with the light reflected from the land around it. This is because the height of a bump is around 1/4 of the wavelength of the light used, so the light falls 1/4 out of phase before reflection and another 1/4 wavelength out of phase after reflection. This causes partial cancellation of

11737-419: The laser's reflection from the surface. By measuring the reflected intensity change with a photodiode , a modulated signal is read back from the disc. To accommodate the spiral pattern of data, the laser is placed on a mobile mechanism within the disc tray of any CD player. This mechanism typically takes the form of a sled that moves along a rail. The sled can be driven by a worm gear or linear motor . Where

11858-428: The late 1980s culminated in development of the 1-bit DAC , which converts high-resolution low-frequency digital input signal into a lower-resolution high-frequency signal that is mapped to voltages and then smoothed with an analog filter. The temporary use of a lower-resolution signal simplified circuit design and improved efficiency, which is why it became dominant in CD players starting from the early 1990s. Philips used

11979-428: The late 1980s culminated in development of the 1-bit DAC , which converts high-resolution low-frequency digital input signal into a lower-resolution high-frequency signal that is mapped to voltages and then smoothed with an analog filter. The temporary use of a lower-resolution signal simplified circuit design and improved efficiency, which is why it became dominant in CD players starting from the early 1990s. Philips used

12100-465: The music industry, audio CDs have been generally sold as either a CD single (now largely dormant), or as full-length albums , the latter of which has been more commonplace since the 2000s. The format has also been influential in the progression of video game music , used in mixed mode CD-ROMs , providing CD-quality audio popularized during the 1990s on hardware such as PlayStation , Sega Saturn and personal computers with 16-bit sound cards like

12221-536: The polycarbonate plastic and aluminium found in CDs. The data integrity of compact discs can be measured using surface error scanning , which can measure the rates of different types of data errors, known as C1 , C2 , CU and extended (finer-grain) error measurements known as E11 , E12 , E21 , E22 , E31 and E32 , of which higher rates indicate a possibly damaged or unclean data surface, low media quality, deteriorating media and recordable media written to by

12342-438: The pregap as index 0 (this latter usage will result in the track playing as the time counter counts down to time 0:00 at the start of the track, index 1.) This is also the case with some discs offering "101 sound effects", with 100 and 101 being indexed as two and three on track 99. The index, if used, is occasionally put on the track listing as a decimal part of the track number, such as 99.2 or 99.3. ( Information Society 's Hack

12463-451: The prior art by Optophonie and James Russell, the information on the disc is read from a reflective layer using a laser as a light source through a protective substrate. Prototypes were developed by Philips and Sony independently in the late 1970s. Although originally 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

12584-489: The raw data stored on the disc. These encoding techniques (defined in the Red Book ) were originally designed for CD Digital Audio , but they later became a standard for almost all CD formats (such as CD-ROM ). CDs are susceptible to damage during handling and from environmental exposure. Pits are much closer to the label side of a disc, enabling defects and contaminants on the clear side to be out of focus during playback. Consequently, CDs are more likely to suffer damage on

12705-432: The same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CDs. CD sales in the United States peaked by 2000. By the early 2000s, the CD player had largely replaced the audio cassette player as standard equipment in new automobiles, with 2010 being the final model year for any car in the United States to have a factory-equipped cassette player. Two new formats were marketed in

12826-432: The same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CDs. CD sales in the United States peaked by 2000. By the early 2000s, the CD player had largely replaced the audio cassette player as standard equipment in new automobiles, with 2010 being the final model year for any car in the United States to have a factory-equipped cassette player. Two new formats were marketed in

12947-488: The same-sized disc. The Mini CD has various diameters ranging from 60 to 80 millimetres (2.4 to 3.1 in); they have been used for CD singles or delivering device drivers . The CD gained rapid popularity in the 1990s, quickly outselling all other audio formats in the United States by 1991, ending the market dominance of the phonograph record and the cassette tape . By 2000, the CD accounted for 92.3% of

13068-511: The standard in 1996. Philips coined the term compact disc in line with another audio product, the Compact Cassette , and contributed the general manufacturing process , based on video LaserDisc technology. Philips also contributed eight-to-fourteen modulation (EFM), while Sony contributed the error-correction method, CIRC, which offers resilience to defects such as scratches and fingerprints. The Compact Disc Story , told by

13189-445: The standard in 1996. Philips coined the term compact disc in line with another audio product, the Compact Cassette , and contributed the general manufacturing process , based on video LaserDisc technology. Philips also contributed eight-to-fourteen modulation (EFM), while Sony contributed the error-correction method, CIRC, which offers resilience to defects such as scratches and fingerprints. The Compact Disc Story , told by

13310-604: The underspecified "four-channel" mode was dropped from the CD standard when it was adopted by the International Electrotechnical Commission and became IEC 908:1987, and later IEC 60908:1999. Since the behavior of the "four-channel" or "Broadcasting use" bit was never specified by either CD standard, no mass-marketed discs have attempted to use the Red Book's four-channel mode, and no players have purported to implement it. The creators of

13431-420: The windings (the pitch ) is 1.6 μm (measured center-to-center, not between the edges). When playing an audio CD, a motor within the CD player spins the disc to a scanning velocity of 1.2–1.4 m/s ( constant linear velocity , CLV)—equivalent to approximately 500 RPM at the inside of the disc, and approximately 200 RPM at the outside edge. The track on the CD begins at the inside and spirals outward so

13552-482: Was adopted by the Digital Audio Disc Committee and ratified by the International Electrotechnical Commission (IEC) Technical Committee 100 as an international standard in 1987 with the reference IEC 60908. The second edition of IEC 60908 was published in 1999 and it replaces the first edition, amendment 1 (1992) and the corrigendum to amendment 1. The IEC 60908 however does not contain all

13673-468: Was an early device that used light for both recording and playback of sound signals on a transparent photograph . More than thirty years later, American inventor James T. Russell has been credited with inventing the first system to record digital media on a photosensitive plate. Russell's patent application was filed in 1966, and he was granted a patent in 1970. Following litigation, Sony and Philips licensed Russell's patents for recording in 1988. It

13794-515: Was chosen because it is half the vertical and half the horizontal resolution of the NTSC video. 352×288 is a similarly one-quarter PAL/SECAM resolution. This approximates the (overall) resolution of an analog VHS tape, which, although it has double the number of (vertical) scan lines, has a much lower horizontal resolution. CD-DA Compact Disc Digital Audio ( CDDA or CD-DA ), also known as Digital Audio Compact Disc or simply as Audio CD ,

13915-464: Was easily made. Sony first publicly demonstrated an optical digital audio disc in September 1976. A year later, in September 1977, Sony showed the press a 30 cm (12 in) disc that could play an hour of digital audio (44,100 Hz sampling rate and 16-bit resolution) using modified frequency modulation encoding. In September 1978, the company demonstrated an optical digital audio disc with

14036-407: Was easily made. Sony first publicly demonstrated an optical digital audio disc in September 1976. A year later, in September 1977, Sony showed the press a 30 cm (12 in) disc that could play an hour of digital audio (44,100 Hz sampling rate and 16-bit resolution) using modified frequency modulation encoding. In September 1978, the company demonstrated an optical digital audio disc with

14157-461: Was granted a patent in 1970. Following litigation, Sony and Philips licensed Russell's patents for recording in 1988. It is debatable whether Russell's concepts, patents, and prototypes instigated and in some measure influenced the compact disc's design. 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. Unlike

14278-535: Was one of very few CD releases to do this, following a release with an equally obscure CD+G feature.) The track and index structure of the CD were carried forward to the DVD format as title and chapter, respectively. Tracks, in turn, are divided into timecode frames (or sectors), which are further subdivided into channel-data frames. The smallest entity in a CD is a channel-data frame , which consists of 33 bytes and contains six complete 16-bit stereo samples: 24 bytes for

14399-510: Was originally intended to be included in CD-DA. The Red Book specification briefly mentioned a four-channel mode in its June 1980, September 1983, and November 1991 editions. On the first page, it lays out the "Main parameters" of the CD system, including: "Number of channels: 2 and/or 4 simultaneously[*] sampled." The footnote says, "In the case of more than two channels the encoder and decoder diagrams have to be adapted." In reality, however,

14520-514: Was published on 1 March 1979. A week later, 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 , later CEO and chairman of Sony, and Heitaro Nakajima were convinced of the format's commercial potential and pushed further development despite widespread skepticism. In 1979, Sony and Philips set up

14641-458: Was published on 1 March 1979. A week later, 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 , later CEO and chairman of Sony, and Heitaro Nakajima were convinced of the format's commercial potential and pushed further development despite widespread skepticism. In 1979, Sony and Philips set up

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