Red Book (audio CD standard)
Overview
 
Red Book is the standard
Standardization
Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....

 for 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 ,...

 (Compact Disc Digital Audio system, CDDA or CD-DA). It is named after one of the Rainbow Books
Rainbow Books
The Rainbow Books are a collection of standards defining the formats of Compact Discs.Red BookYellow BookThe Rainbow Books are a collection of standards defining the formats of Compact Discs.Red Book...

, a series of books (bound in different colors) that contain the technical specifications
Specification (technical standard)
A specification is an explicit set of requirements to be satisfied by a material, product, or service. Should a material, product or service fail to meet one or more of the applicable specifications, it may be referred to as being out of specification;the abbreviation OOS may also be used...

 for all CD and CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

 formats.

The first edition of the Red Book was released in 1980 by Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

 and Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

; it was adopted by the Digital Audio Disc Committee and ratified as IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...

 60908 (published in 1987).
Encyclopedia
Red Book is the standard
Standardization
Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....

 for 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 ,...

 (Compact Disc Digital Audio system, CDDA or CD-DA). It is named after one of the Rainbow Books
Rainbow Books
The Rainbow Books are a collection of standards defining the formats of Compact Discs.Red BookYellow BookThe Rainbow Books are a collection of standards defining the formats of Compact Discs.Red Book...

, a series of books (bound in different colors) that contain the technical specifications
Specification (technical standard)
A specification is an explicit set of requirements to be satisfied by a material, product, or service. Should a material, product or service fail to meet one or more of the applicable specifications, it may be referred to as being out of specification;the abbreviation OOS may also be used...

 for all CD and CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

 formats.

The first edition of the Red Book was released in 1980 by Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

 and Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

; it was adopted by the Digital Audio Disc Committee and ratified as IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...

 60908 (published in 1987). The second edition of IEC 60908 was published in 1999 and it cancels and replaces the first edition, amendment 1 (1992) and the corrigendum to amendment 1. The standard is not freely available and must be licensed from Philips.

Red Book audio specifications

The basic specifications state that
  1. Maximum playing time is 79.8 minutes
  2. Minimum duration for a track
    Track (CD)
    On an optical disc, a track or title is a subdivision of its content. Specifically, it is a consecutive set of sectors on the disc containing a block of data. One session may contain one or more tracks of the same or different types...

     is 4 seconds (including 2-second pause)
  3. Maximum number of tracks is 99
  4. Maximum number of index points (subdivisions of a track) is 99 with no maximum time limit
  5. International Standard Recording Code
    International Standard Recording Code
    The International Standard Recording Code , defined by ISO 3901, is an international standard code for uniquely identifying sound recordings and music video recordings. IFPI has been appointed by ISO as registration authority for this standard. The ISO technical committee 46, subcommittee 9 is...

     (ISRC) should be included

Technical details

The Red Book specifies the physical parameters and properties of the CD, the optical "stylus" parameters, deviations and error rate, modulation system (eight-to-fourteen modulation
Eight-to-Fourteen Modulation
Eight-to-fourteen modulation is a data encoding technique – formally, a channel code – used by compact discs and pre-Hi-MD MiniDiscs. EFMPlus is a related code, used in DVDs and SACDs. EFM and EFMPlus were both invented by Kees A...

, EFM) and error correction (cross-interleaved Reed-Solomon coding
Cross-Interleaved Reed-Solomon Coding
In the compact disc system, cross-interleaved Reed-Solomon code provides error detection and error correction. CIRC adds to every three data bytes one redundant parity byte.-Overview:...

, CIRC), and subcode channels
Compact disc subcode
Besides digital audio, a compact disc contains digital data called subcode or subchannel data, which is multiplexed with the digital audio. The data in a CD are arranged in frames. A frame comprises 33 bytes, of which 24 bytes are audio , eight bytes are error correction , and one byte is for subcode...

 and graphics.

It also specifies the form of digital audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...

 encoding: 2-channel signed
Signedness
In computing, signedness is a property of data types representing numbers in computer programs. A numeric variable is signed if it can represent both positive and negative numbers, and unsigned if it can only represent non-negative numbers .As signed numbers can represent negative numbers, they...

 16-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...

 Linear PCM sampled at 44,100 Hz
44,100 Hz
In digital audio, 44,100 Hz is a common sampling frequency: analog audio is recorded by sampling it 44,100 times per second, and then these samples are used to reconstruct the audio signal when playing it back...

. This sample rate is adapted from that attained when recording digital audio on a PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...

 (or NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...

) videotape
Videotape
A videotape is a recording of images and sounds on to magnetic tape as opposed to film stock or random access digital media. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram...

 with a PCM adaptor
PCM adaptor
A PCM adaptor is a device used for recording digital audio in the PCM format, which in turn connects to a video cassette recorder for storage and playback of the digital audio information.-How a PCM adaptor works:...

, an earlier way of storing digital audio.

An audio CD can represent frequencies up to 22.05 kHz, the Nyquist frequency
Nyquist frequency
The Nyquist frequency, named after the Swedish-American engineer Harry Nyquist or the Nyquist–Shannon sampling theorem, is half the sampling frequency of a discrete signal processing system...

 of the 44.1 kHz sample rate.

The audio bit rate
Bit rate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....

 is 1,411.2 kbit/s:
2 channels x 44,100 samples per second per channel × 16 bits per sample = 1,411,200 bit/s = 1,411.2 kbit/s.


As each sample is a signed
Signedness
In computing, signedness is a property of data types representing numbers in computer programs. A numeric variable is signed if it can represent both positive and negative numbers, and unsigned if it can only represent non-negative numbers .As signed numbers can represent negative numbers, they...

 16-bit two's complement
Two's complement
The two's complement of a binary number is defined as the value obtained by subtracting the number from a large power of two...

 integer
Integer (computer science)
In computer science, an integer is a datum of integral data type, a data type which represents some finite subset of the mathematical integers. Integral data types may be of different sizes and may or may not be allowed to contain negative values....

, sample values range from −32768 to +32767.

On the disc, the data is stored in sectors of 2352 bytes each, read at 75 sectors per second. Onto this the overhead of EFM, CIRC, L2 ECC, eight subcode data channels, and so on, is added, but these are not typically exposed to the application reading the disc. Because of this overhead, the raw bitrate (at the optical pickup) is considerably higher than the audio bitrate.

By comparison, the bit rate of a "1x" data CD is defined as 2048 bytes per sector × 75 sectors per second = 150 KiB
Kibibyte
The kibibyte is a multiple of the unit byte for quantities of digital information. The binary prefix kibi means 1024; therefore, 1 kibibyte is . The unit symbol for the kibibyte is KiB. The unit was established by the International Electrotechnical Commission in 1999 and has been accepted for use...

/s (1228.8 kbit/s), or approximately 9.2 million byte
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...

s per minute.

Format Deviations

Some major recording publishers have begun to sell CDs that violate the Red Book standard. Some do so for the purpose of copy prevention
Copy protection
Copy protection, also known as content protection, copy obstruction, copy prevention and copy restriction, refer to techniques used for preventing the reproduction of software, films, music, and other media, usually for copyright reasons.- Terminology :Media corporations have always used the term...

, using systems like Copy Control
Copy Control
Copy Control was the generic name of a copy prevention system, used from 2001 until 2006 on several digital audio disc releases by EMI Group and Sony BMG Music Entertainment in several regions...

.

Some do so for extra features such as 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...

, which includes both a CD layer and a DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

 layer whereby the CD layer is much thinner, 0.9 mm, than required by the Red Book, which stipulates a nominal 1.2 mm, but at least 1.1 mm. Philips and many other companies have warned them that including the Compact Disc Digital Audio logo on such non-conforming discs may constitute trademark
Trademark
A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...

 infringement. Either in anticipation or in response, recent copy-protected CDs bear stickers and warnings that the CD is not standard and may not play in all CD players, and no longer display the long-familiar logo.

In the beginning of the 21st century, two advanced versions of the audio CD emerged: the 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...

 and DVD Audio. The two rival formats were designed to feature audio of higher fidelity. Both formats apply a higher sampling rate and use 650 nm lasers.

Availability

The standard is available from Phillips and the IEC. As of 2004, the cost per the relevant Philips order form is US$5,000. As of 2009, the IEC 60908 document is available as a PDF download for US$260.

See also

  • Extended Copy Protection
    Extended Copy Protection
    Extended Copy Protection is a software package developed by the British company First 4 Internet, and sold as a copy protection or digital rights management scheme for Compact Discs...

    —source of the Sony DRM scandal
    2005 Sony BMG CD copy protection scandal
    The Sony BMG CD copy protection rootkit scandal concerns the copy protection measures included by Sony BMG on Compact Discs in 2005. Sony BMG included the Extended Copy Protection and MediaMax CD-3 software on music CDs. XCP was put on 52 titles and MediaMax was put on 50 titles...

  • DRM (computing)
  • Four-channel compact disc digital audio
    Four-channel compact disc digital audio
    Compact Disc recordings contain two channels of 44.1-kHz 16-bit linear PCM audio. However, creators of the CD originally contemplated a four-channel, or quadraphonic, mode as well....

  • WAV
    WAV
    Waveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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