Rainbow Books
With Rainbow Books ( English for Rainbow Books and rainbow-colored books ), the official standards of the compact disc , shortly CD called. Corresponding CDs may be marked with one of the standardized CD logos . Each standard is assigned a color that is reflected in the cover color of the standard work (book) in which it was published.
Red Book: audio CD
The Red Book (English for Red Book ) contains the technical specifications of the Compact Disc Digital Audio (CD-DA, CD) and was developed by Philips and Sony in 1980 established. It is the first CD standard to describe the physical division (blocks, frames with 24 byte capacity, etc.), the error correction mechanism and the coding process . CDs according to this standard store stereo audio data with 16- bit resolution and a sampling rate of 44.1 kHz . A CD according to the Red Book standard may contain a maximum of 99 tracks (titles). Each track must be at least four seconds long. The track pre-gap is located between the tracks, which for standard-compliant audio CDs must have a length of at least two seconds and the audio idle level. The maximum playing time is 79.8 minutes. The maximum number of index points per track is 99, with no maximum time limit. The ISRC (ISO 3901) should be included. The audio CD can store frequencies of up to 22.05 kHz, which also corresponds to the Nyquist frequency at a sampling rate of 44.1 kHz. The bit rate is 1411.2 kbps .
From today's perspective, audio CDs only have to guarantee the low transfer rate of 176.4 kB / s (corresponding to a transfer rate of 75 blocks per second). Due to this low requirement and the associated low number of revolutions, so-called shape CDs were possible, CDs with contours deviating from the circle and possible imbalances. Playing at speeds higher than 1 × (as is common with CD-ROM drives) can damage the drive. Shape CDs have almost completely disappeared from the market today. The symmetrical business card CDs are an exception.
The Red Book only defines the pure audio CD, which does not use any data tracks or copy protection mechanisms. Hybrid CDs (audio tracks and a computer data track) are defined in the Blue Book (CD-Extra).
Copy-protected audio CDs do not correspond to any standard of book terminology (including the Red Book), since these standards are deliberately violated. This happens, for example, through faulty data, which are designed in such a way that most pure audio CD players are not irritated by them; see also Compact Disc Digital Audio: Copy Protection .
Yellow Book: CD-ROM
The Yellow Book (English for Yellow Book ) is the 1985 standard for data CDs ( CD-ROM ) and an extension of the Red Book. It is independent of the operating system.
In contrast to the standard for audio CDs specified in the Red Book, according to the Yellow Book, the sectors of a CD-ROM must be individually addressable, which makes continuous addressing necessary at the beginning of each sector. There are also two different so-called recording methods, of which only one can be used per sector .
The Yellow Book provides two modes:
CD-ROM mode 1
The more common mode 1 enables a storage capacity of 2048 bytes per sector . In addition to the error correction ( LEC ) already defined in the Red Book , additional correction data (12 bytes sync, 288 bytes FEC ) are used, which lowers the average error rate by many orders of magnitude, but at the same time reduces the user data per sector. The block size, together with the transmission rate of 75 blocks per second on which the audio CD is based, defines the reference variable 1 × speed as 2048 B · 75 s −1 = 153.6 kB / s.
CD-ROM mode 2
In contrast to mode 1, CD-ROM mode 2 does not contain any additional error correction ( LEC ), which increases the storage capacity of the sectors to 2336 bytes . Because of this missing addition, mode 2 was only used for video and audio data and never achieved the spread of mode 1. It was replaced by CD-ROM / XA , which was defined in an expanded version of the Yellow Book. This standard is sometimes erroneously referred to as CD-ROM Mode 2.
The revised version of this standard is also known as the High Sierra and corresponds to the ISO 9660 standard , which regulates, among other things, how the data is stored on the CD-ROM.
In 1989 Philips , Microsoft and Sony agreed on the first CD-ROM / XA specification, which was revised in 1991 in the so-called Extended Yellow Book .
File systems
The Yellow Book only specifies at a low level, close to the hardware, how bits are stored on the CD. In order to ensure that data is stored largely independently of the device and operating system, file system standards based on the Yellow Book were introduced at a more abstract level : First the ISO-9660 standard, then Joliet and Rockridge as an extension .
Literature / web links
The Yellow Book was published by Philips and Sony only for their licensees; even today it is only available direct from Philips, priced at $ 100 (individually, 2005). The content of the Yellow Book corresponds to the later adopted standards ISO / IEC 10149 and ECMA 130, the latter is freely downloadable from the following address:
Blue Book: Enhanced CD
The Blue Book standard (English for Blue Book ) dates back to 1995 and describes so-called Advanced music CDs (Enhanced Music CD, Enhanced CD, CD Extra). These are pressed CDs that contain audio data (up to 98 tracks) in the first session and computer-readable data in a second session.
With this division into two parts, the Blue Book standard enables the manufacturer to write additional information on the CD in addition to the audio data, without reducing playback comfort. If you play computer data on an audio CD player, in the best case you will hear silence or a kind of white noise , in the worst case the speakers and hearing will be damaged. The playback of the computer data accommodated in the second session is prevented by the fact that conventional CD players only access the first session of a CD. Computers, on the other hand, have access to both sessions, including all of the contents of the CD.
The content of the data in the second session does not have to be related to the audio tracks, although they usually relate to them (images, videos or other multimedia content).
Green Book: CD-i
In the Green Book (English for Green Book ) is data format for so-called CD-i data media held (CD-Interactive). It was released by Philips and Sony in September 1990 . It essentially consists of an operating system (CD-RTOS), a decoder (MC 68000) and AV components . The special thing is that it has data and an application program. The sector format is structured in the same way as the CD-ROM XA. The resolution is 360 × 240 picture elements. An extension enables full-screen playback of MPEG-1 according to ISO 11172 .
The following variants also exist:
- CD-I-Ready (similar to CD-DA ; enables playback of the audio information on the CD-i)
- CD-Bridge (connection of CD-ROM XA and CD-i, contains CD data according to CD-DA standard and CD-i application)
Orange Book: CD-R
The Orange Book (for English Orange Book ) describes recordable CD formats with multi-session capability. It was first published in 1990 and consists of three parts:
- CD-MO : Magneto Optical Disks ( Magneto Optical Disk )
- CD-R : write- once CDs (so-called WORMs )
- CD-RW : rewritable CD media
The Orange Book contains the specifications for both blank and recorded media from the above category. In addition, the data organization and recommendations for measuring the quality are described.
The Orange Book was last amended in 2002.
White Book: Video CD
The White Book (English for white book ), a standard that was set in 1993 by Philips and JVC initially for karaoke CDs, describes the basics of the video CD (VCD) (1995). Until 1998 it was expanded to include the option of linking to websites and improving video quality through higher-resolution formats (via MPEG-2 ).
Beige Book: Photo CD
The Beige Book (English for beige book ) is the standard of the Photo CD .
Scarlet Book: Super Audio CD
The Scarlet Book (English for Scarlet book ) describes the standard for Super Audio CD .
Purple Book: Double Density CD
The Purple Book (English for Violettes book ) describes the standard for double-density CD (DDCD).