High Definition Compatible Digital
Encyclopedia
High Definition Compatible Digital, or HDCD is a patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

ed encode-decode
Encoder
An encoder is a device, circuit, transducer, software program, algorithm or person that converts information from one format or code to another, for the purposes of standardization, speed, secrecy, security, or saving space by shrinking size.-Media:...

 process, now owned by Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

, that improves the audio quality of standard Redbook
Red Book (audio CD standard)
Red Book is the standard for audio CDs . It is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.The first edition of the Red Book was released in 1980 by Philips and Sony; it was adopted by the Digital Audio Disc...

 audio CDs
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

, while retaining backward compatibility
Backward compatibility
In the context of telecommunications and computing, a device or technology is said to be backward or downward compatible if it can work with input generated by an older device...

 with existing Compact disc player
Compact disc player
A Compact Disc player , or CD player, is an electronic device that plays audio Compact Discs. CD players are often a part of home stereo systems, car audio systems, and personal computers. They are also manufactured as portable devices...

s.
At over 5,000 titles, HDCD-encoded releases constitute a fraction of the total CD commercial music catalog.

A number of universal CD and DVD players include HDCD decoding, and version 9 and above of the Windows Media Player
Windows Media Player
Windows Media Player is a media player and media library application developed by Microsoft that is used for playing audio, video and viewing images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices...

 software (on personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s with a 24-bit sound card
Sound card
A sound card is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware...

) are capable of decoding HDCD.

An HDCD-encoded CD usually, but not always, has the HDCD logo printed on the back cover. An HDCD logo may also be displayed in Windows Media Player 9 or above when an HDCD encoded disc is played.

Technical overview

HDCD encodes the equivalent of 20 bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...

s worth of data in a 16-bit digital audio signal by using custom dither
Dither
Dither is an intentionally applied form of noise used to randomize quantization error, preventing large-scale patterns such as color banding in images...

ing, audio filter
Audio filter
An audio filter is a frequency dependent amplifier circuit, working in the audio frequency range, 0 Hz to beyond 20 kHz. Many types of filters exist for applications including graphic equalizers, synthesizers, sound effects, CD players and virtual reality systems.Being a frequency dependent...

s, and some reversible amplitude and gain encoding; Peak Extend, which is a reversible soft limiter and Low Level Range Extend, which is a reversible gain on low-level signals. There is thus a benefit at the expense of a very minor increase in noise.

HDCD encoding places a control signal in the least-significant bit of a small subset of the 16-bit Red Book
Red Book (audio CD standard)
Red Book is the standard for audio CDs . It is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.The first edition of the Red Book was released in 1980 by Philips and Sony; it was adopted by the Digital Audio Disc...

 audio samples (a technique known as in-band signaling
In-band signaling
In telecommunications, in-band signaling is the sending of metadata and control information in the same band or channel used for data.-Telephone:...

). The HDCD decoder in the consumer's CD / DVD player, or in some cases audio receiver, if present, responds to the signal. If no decoder is present, the disc will be played as a regular CD.

In itself, the use of the first bit in the dithered least-significant bit stream will degrade the sound quality on a non-HDCD player by decreasing the signal-to-noise ratio
Signal-to-noise ratio
Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise...

 but only by a minuscule amount. HDCD Peak Extension, if chosen in HDCD mastering, will apply compression to the peaks which will be audible in playback on a non-HDCD system which does not apply the appropriate expansion curve.

HDCD provides several digital features, which the audio mastering
Audio mastering
Mastering, a form of audio post-production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device ; the source from which all copies will be produced...

 engineer controls at his/her own discretion. They include
  • Dynamic range
    Dynamic range
    Dynamic range, abbreviated DR or DNR, is the ratio between the largest and smallest possible values of a changeable quantity, such as in sound and light. It is measured as a ratio, or as a base-10 or base-2 logarithmic value.-Dynamic range and human perception:The human senses of sight and...

     compression and expansion, with which virtually four more bits of dynamic range can be added to the musical signal.
  • Precision digital interpolation
    Interpolation
    In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points....

     filtering with multiple modes of operation, which can reduce alias distortion
    Aliasing
    In signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable when sampled...

     and temporal
    Time
    Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....

     smearing, resulting in a more natural, open, and accurate sound reproduction.

History

HDCD technology was developed between 1986 and 1991 by "Professor" Keith O. Johnson and Michael "Pflash" Pflaumer of Pacific Microsonics Inc. It was made publicly available as HDCD-enabled audio CDs in 1995.

In 2000, Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

 acquired the company and all of its intellectual property
Intellectual property
Intellectual property is a term referring to a number of distinct types of creations of the mind for which a set of exclusive rights are recognized—and the corresponding fields of law...

 assets.

There have been a number of players and processors over the years that were capable of properly decoding the information from HDCDs. Included were those from Spectral (USA), California Audio Labs (USA), Mark Levinson/Madrigal (USA), Arcam (UK), Burmester (Germany), Cary (USA), Naim
Naim Audio
Naim Audio is a British manufacturer of high fidelity audio products for domestic use, based in Salisbury, Wiltshire, United Kingdom.-History:...

 (UK), Linn
Linn Products
Linn Products is a Scottish company, based in Glasgow, that manufactures hi-fi audio equipment, home theatre, and multi-room integrated audio systems...

 (UK), Classe (Canada), A&R Cambridge Ltd (ARCAM)
A&R Cambridge Ltd (ARCAM)
A&R Cambridge Ltd is a British manufacturer of hi-fi equipment based in Waterbeach Cambridgeshire, England, UK. It was formally established in 1976 by science and engineering students from the University of Cambridge. John Dawson, one of the Cambridge graduates, is still with ARCAM.A&R...

 (UK), Denon
Denon
is a Japanese electronics company that was involved in the early stages of development of digital audio technology, while specializing in the manufacture of high-fidelity professional and consumer audio equipment. For many decades, Denon was a brand name of Nippon-Columbia, including the Nippon...

 (Japan), Rotel
Rotel
Rotel is a Japanese manufacturer of high end audio and video equipment: home theater, amplifiers, compact disc players, etc. The company was established in 1966. The company was formed by the "elder" Tachikowa and currently run by the son, Bob Tachikowa...

 (Japan) and Cayin-Spark (China) plus all the OPPO universal players. Outboard DACs (digital to analog converters) were produced by Berkeley Audio Design, Spectral, Classe, Mark Levinson, and others.

In 1998, Burr-Brown (now part of Texas Instruments) and Sanyo Electronics of Japan introduced low cost D to A converters with HDCD decoding included, allowing HDCD to be used in CD and DVD players in the $100 range. HDCD algorithms were included in DVD chips from many IC makers including Motorola and C-Cubed, allowing HDCD to be offered by mass-market DVD player makers such as Panasonic and Toshiba. As of 2007, a number of players continue to feature HDCD capability, including Harman Kardon
Harman Kardon
harman/kardon is a division of Harman International Industries and manufactures home and car audio equipment.Founded in 1953 by Dr. Sidney Harman and Bernard Kardon — two men with a deep interest in music and the arts — the company helped create the high-fidelity audio industry. Their first product...

, Denon
Denon
is a Japanese electronics company that was involved in the early stages of development of digital audio technology, while specializing in the manufacture of high-fidelity professional and consumer audio equipment. For many decades, Denon was a brand name of Nippon-Columbia, including the Nippon...

, Marantz
Marantz
Marantz is a company that develops and sells upper-mid range to high-end audio products.The first Marantz audio product was designed and built by Saul B. Marantz in his home in Kew Gardens, New York...

, Cary, Rotel, Mark Levinson, Shanling, NAD, Spectral. More recently the Oppo line of players all feature HDCD decoding.

There are no labels that record and release only HDCDs. Reference Recordings has produced many classical CDs in the HDCD format, which include new releases and have won numerous awards. Linn Records
Linn Records
Linn Records is a Glasgow-based record label which specialises in classical, jazz and Scottish music. It is part of Linn Products.-History:While Linn engineers were testing their flagship product, the Sondek LP12 turntable, they became frustrated with some of the specialist test LPs they were using...

 has a number of hybrid HDCD / SACDs, and also seem to enjoy a good reputation among music enthusiasts.

As for "mainstream" popular artists, Laurie Anderson
Laurie Anderson
Laura Phillips "Laurie" Anderson is an American experimental performance artist, composer and musician who plays violin and keyboards and sings in a variety of experimental music and art rock styles. Initially trained as a sculptor, Anderson did her first performance-art piece in the late 1960s...

, Lifehouse
Lifehouse (band)
Lifehouse is an American rock band from Los Angeles. The band came to mainstream prominence in 2001 with the hit single "Hanging by a Moment" from their debut studio album, No Name Face. The single won a Billboard Music Award for Hot 100 Single of the Year, beating out Janet Jackson and Alicia...

, John Mellencamp
John Mellencamp
John Mellencamp, previously known by the stage names Johnny Cougar, John Cougar, and John Cougar Mellencamp, is an American rock singer-songwriter, musician, painter and occasional actor known for his catchy, populist brand of heartland rock that eschews synthesizers and other artificial sounds...

, Lee Ann Womack
Lee Ann Womack
Lee Ann Womack is an American country music singer and songwriter, who is best known for her old fashioned-styled country music songs that often discuss subjects such as cheating and lost love....

, Tool
Tool (band)
Tool is an American rock band from Los Angeles, California. Formed in 1990, the group's line-up has included drummer Danny Carey, guitarist Adam Jones, and vocalist Maynard James Keenan. Since 1995, Justin Chancellor has been the band's bassist, replacing their original bassist Paul D'Amour...

, The Beach Boys
The Beach Boys
The Beach Boys are an American rock band, formed in 1961 in Hawthorne, California. The group was initially composed of brothers Brian, Dennis and Carl Wilson, their cousin Mike Love, and friend Al Jardine. Managed by the Wilsons' father Murry, The Beach Boys signed to Capitol Records in 1962...

, Beck
Beck
Beck Hansen is an American musician, singer-songwriter and multi-instrumentalist, known by the stage name Beck...

, The Grateful Dead
Grateful Dead
The Grateful Dead was an American rock band formed in 1965 in the San Francisco Bay Area. The band was known for its unique and eclectic style, which fused elements of rock, folk, bluegrass, blues, reggae, country, improvisational jazz, psychedelia, and space rock, and for live performances of long...

, Jerry Garcia
Jerry Garcia
Jerome John "Jerry" Garcia was an American musician best known for his lead guitar work, singing and songwriting with the band the Grateful Dead...

, Madonna
Madonna (entertainer)
Madonna is an American singer-songwriter, actress and entrepreneur. Born in Bay City, Michigan, she moved to New York City in 1977 to pursue a career in modern dance. After performing in the music groups Breakfast Club and Emmy, she released her debut album in 1983...

, Mark Knopfler
Mark Knopfler
Mark Freuder Knopfler, OBE is a Scottish-born British guitarist, singer, songwriter, record producer and film score composer. He is best known as the lead guitarist, vocalist, and songwriter for the British rock band Dire Straits, which he co-founded in 1977...

, King Crimson
King Crimson
King Crimson are a rock band founded in London, England in 1969. Often categorised as a foundational progressive rock group, the band have incorporated diverse influences and instrumentation during their history...

, Roxy Music
Roxy Music
Roxy Music was a British art rock band formed in 1971 by Bryan Ferry, who became the group's lead vocalist and chief songwriter, and bassist Graham Simpson. The other members are Phil Manzanera , Andy Mackay and Paul Thompson . Former members include Brian Eno , and Eddie Jobson...

 (also Bryan Ferry
Bryan Ferry
Bryan Ferry, CBE is an English singer, musician, and songwriter. Ferry came to public prominence in the early 1970s as lead vocalist and principal songwriter with the band Roxy Music, who enjoyed a highly successful career with three number one albums and ten singles entering the top ten charts in...

), Van Halen
Van Halen
Van Halen is an American hard rock band formed in Pasadena, California, in 1972. The band has enjoyed success since the release of its debut album, Van Halen, . As of 2007 Van Halen has sold 80 million albums worldwide and has had the most #1 hits on the Billboard Mainstream Rock chart...

, Joni Mitchell
Joni Mitchell
Joni Mitchell, CC is a Canadian musician, singer songwriter, and painter. Mitchell began singing in small nightclubs in her native Saskatchewan and Western Canada and then busking in the streets and dives of Toronto...

, Neil Young
Neil Young
Neil Percival Young, OC, OM is a Canadian singer-songwriter who is widely regarded as one of the most influential musicians of his generation...

, Mannheim Steamroller
Mannheim Steamroller
Mannheim Steamroller is an American music group founded by Chip Davis and Jackson Berkey, known primarily for its modern recordings of Christmas music. The group has sold 28 million albums in the U.S. alone.-Beginnings:...

, Kenny Chesney
Kenny Chesney
Kenneth "Kenny" Arnold Chesney is an American country music singer and songwriter. Chesney has recorded 15 albums, 14 of which have been certified gold or higher by the RIAA. He has also produced more than 30 Top Ten singles on the U.S...

, Dixie Chicks
Dixie Chicks
The Dixie Chicks are an American country band which has also successfully crossed over into other genres. The band is composed of founding members Martie Erwin Maguire and Emily Erwin Robison, and lead singer Natalie Maines...

, The B-52's
The B-52's
The B-52's are an American rock band, formed in Athens, Georgia in 1976. The original line-up consisted of Fred Schneider , Kate Pierson , Cindy Wilson , Ricky Wilson , and Keith Strickland . Following Ricky Wilson's death in 1985 Strickland switched to guitar...

, NOFX
NOFX
NOFX is an American punk rock band from Los Angeles, California .The band was formed in 1983 by vocalist/bassist Fat Mike and guitarist Eric Melvin. Drummer Erik Sandin joined NOFX shortly after. In 1991 El Hefe joined to play lead guitar and trumpet, rounding out the current line-up...

, Da Brat
Da Brat
Shawntae Harris , better known as Da Brat, is an American rapper and actress. Her debut album, Funkdafied, sold one million copies, making her the first female rapper to have a platinum-selling album.-Early life:...

, Natalie Merchant
Natalie Merchant
Natalie Anne Merchant is an American singer-songwriter and musician. She joined the alternative rock band 10,000 Maniacs in 1981 and left it to begin her solo career in 1993.-Early life:...

, Lucinda Williams
Lucinda Williams
Lucinda Williams is an American rock, folk, blues and country music singer and songwriter. She recorded her first albums in 1978 and 1980 in a traditional country and blues style and received very little attention from radio, the media, or the public. In 1988, she released her self-titled album,...

, and Mike Oldfield
Mike Oldfield
Michael Gordon Oldfield is an English multi-instrumentalist musician and composer, working a style that blends progressive rock, folk, ethnic or world music, classical music, electronic music, New Age, and more recently, dance. His music is often elaborate and complex in nature...

 have released albums on HDCD. As of January 2007, there are roughly the same number of titles released on SACD
Super Audio CD
Super Audio CD is a high-resolution, read-only optical disc for audio storage. Sony and Philips Electronics jointly developed the technology, and publicized it in 1999. It is designated as the Scarlet Book standard. Sony and Philips previously collaborated to define the Compact Disc standard...

 as on HDCD-encoded CDs.

Windows Media Player

Since Windows Media Player
Windows Media Player
Windows Media Player is a media player and media library application developed by Microsoft that is used for playing audio, video and viewing images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices...

 9 for Windows XP, PCs are capable of decoding and playing HDCDs on personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s with a 24-bit sound card
Sound card
A sound card is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware...

 installed. Media Player 9 indicates the presence of an HDCD by flashing the logo in the control bar at the bottom of the application window. This was changed in versions 10 and 11; if an HDCD is inserted into a drive with WMP 10/11 running, the HDCD logo appears only if the HDCD feature is disabled, thus, signalling that it should be enabled for proper decoding.

This feature must be enabled by changing a WMP speakers setting involving 24-bit audio. The path to this setting is found in the Player's Options control panel which can be accessed from the Tools menu: Tools/Options/Devices/Speakers/Properties/Performance.

Due to player design, the HDCD decoding is placed within the CD read chain. Thus, HDCD decoding can only be achieved whilst directly playing back HDCD-formatted disks. The Windows Media Player software is not currently able to decode HDCD information present from ripped images of disks. However, Media Player 9 is able to recognize copies of HDCDs.

Windows Media Player does not decode HDCD audio streams during ripping and the decoded encoded extra HDCD information is lost (but the information is maintained provided the data is stored in a lossless format). By using a WAV
WAV
Waveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...

 output recorded plugin, it is possible to grab a perfect digital copy of a decoded HDCD stream, which can then be used for encoding into other formats.

In some HDCD discs, and some DVD players using WMP, the first track is not recognized as HDCD but all other tracks are, ("if played a few seconds early or a few seconds before the actual song") at the end of the previous track, that is because HDCD has a control signal, if that control signal is not detected by WMP at the beginning of the song, the HDCD decoder is not activated.

Software decoders

A member of the Doom9 forum
Doom9
Doom9 is a website featuring information on digital audio and video manipulation, mostly video, and digital copyrights. It is also the forum username of the author of the page, an Austrian then college student at the time of the creation of the site...

 has authored a Windows CLI
Command-line interface
A command-line interface is a mechanism for interacting with a computer operating system or software by typing commands to perform specific tasks...

 utility, hdcd.exe, to extract and decode the HDCD data in 16-bit WAV
WAV
Waveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...

 files ripped
CD ripper
A CD ripper, CD grabber or CD extractor is software that convert tracks on a CD to standard computer sound files, such as WAV, MP3, or Ogg Vorbis.It rips raw digital audio in CDDA format on a compact disc to a file or other output.- History :...

 from HDCD discs. This utility writes a 24-bit WAV output files with four bits of padding per sample. The author of the utility decided not to make the source code publicly available as the HDCD technology is patented.

Illustrate's dBpoweramp Music Converter, a Windows GUI
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 program, has an HDCD DSP
Digital signal processing
Digital signal processing is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing...

 effect that acts as a front-end to the utility listed above.

A plugin is available for foobar2000
Foobar2000
foobar2000 is a freeware audio player for Windows developed by Peter Pawlowski, a former freelance contractor for Nullsoft. It is known for its highly modular design and extensive SDK which allows third-party developers to do such things as completely replace the interface...

 that will decode HDCD data in any 16-bit PCM passed through it, resulting in a 20-bit PCM stream.

See also

  • XRCD
  • Super Audio CD
    Super Audio CD
    Super Audio CD is a high-resolution, read-only optical disc for audio storage. Sony and Philips Electronics jointly developed the technology, and publicized it in 1999. It is designated as the Scarlet Book standard. Sony and Philips previously collaborated to define the Compact Disc standard...

  • DVD-Audio
    DVD-Audio
    DVD-Audio is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio is not intended to be a video delivery format and is not the same as video DVDs containing concert films or music videos....

  • DualDisc
    DualDisc
    DualDisc was a type of double-sided optical disc product developed by a group of record companies including EMI Music, Universal Music Group, Sony/BMG Music Entertainment, Warner Music Group, and 5.1 Entertainment Group and later under the aegis of the Recording Industry Association of America...

  • K2 High Definition
    K2 High Definition
    K2 High Definition is a mastering technique developed by JVC Music. K2 HD encodes the music in 24 bit and 100 kHz resolution while in the mastering stage, even though the end product is a standard red book CD and does not require special hardware for playback.-External links: *...

  • Super Bit Mapping
    Super Bit Mapping
    Super Bit Mapping is a Noise Shaping process, developed by Sony for CD mastering.Sony's SBM, a process that is intended to raise the standard of 16-Bit recording and playback quality...


External links

  • http://web.archive.org/web/20050622080528/http://www.hdcd.com/ last Internet Archive
    Web ARChive
    The Web ARChive archive format specifies a method for combining multiple digital resources into an aggregate archive file together with related information. The WARC format is a revision of the Internet Archive's ARC File Format [ARC_IA] that has traditionally been used to store "web crawls" as...

     capture of Mirosoft's now discontinued HDCD official website
  • http://web.archive.org/web/20041204171913/www.hdcd.com/about/whatisHDCD.html last Internet Archive
    Web ARChive
    The Web ARChive archive format specifies a method for combining multiple digital resources into an aggregate archive file together with related information. The WARC format is a revision of the Internet Archive's ARC File Format [ARC_IA] that has traditionally been used to store "web crawls" as...

    capture of Mirosoft's now discontinued HDCD official FAQ
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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