Compact Disc Fundamentals
Unlike magnetic storage devices, which store data on multiple concentric tracks, all CD formats store data on one physical track, which spirals continuously from the center to the outer edge of the recording area. All CD formats use 3,234-byte physical sectors, which allocate 882 bytes to control and error correction data, leaving 2,352 bytes available. Different CD formats use this space differently: audio CDs use the entire 2,352 bytes to store audio data; computer CDs use only 2,048 bytes to store user data, and allocate the remaining 304 bytes to store additional ECC and control data, including header data and synchronization data. (Audio CDs are addressable to within one second; computer CDs must be addressable by sector, or 1/75 of a second.) Sectors are grouped as logical numbered tracks, which are listed in the Table of Contents (TOC) for the disc, a special unnumbered track that is analogous to the File Allocation Table and root directory on a computer disk.
All current CD formats derive from the original Compact Disc-Digital Audio (CD-DA) format introduced in 1974 as a replacement for vinyl record albums. The following standards define the formats used for compact discs:
- Red Book
The original CD standard that defines CD-DA (the audio CD), a method that allows digital recording of 74 minutes of audio separated into tracks. Red Book also defines CD infrastructure, including disc dimensions, optical stylus, modulation and error correction standards, ...