There are six standards for CD discs
1. Red Book
The Red Book defines CD-DA (Digital Audio) specifications, and CD-DA is referred to as digital music disc. This was formulated by PHILIPS and SONY in 1980, and all subsequent optical disc specifications were developed based on this.
Initially, the playback time of digital music discs could be up to 60 minutes, and later it was improved and evolved to 74 minutes as the final standard.
Audio CD samples music in 44.1KHz sampling frequency units, and each sampling unit converts the digital signal into a 16-bit range value to convert analog to digital data. This binary code also needs to go through 8 The digitization operation is completed at 14 encoding (EFM Modulator), and then the 0 and 1 signals are converted into pit (signal pit) and land (signal surface) on the CD, and finally placed on the spiral track (track).
The main function of CD-Audio discs is to play music, and it is played sequentially. Each song is played from the beginning to the end. Therefore, the specifications of the Red Book were very simple and complete at the time. The main purpose is to provide a standard playback specification so that all CD discs can play music on all CD speakers.
2. Yellow Book
The Yellow Book defines the specifications of CD-ROM (Compact Disc-Read Only Memory). CD-ROM is referred to as read-only disc. Philips and Sony published the Yellow Book in 1983. The Yellow Book is based on the Red Book. The data stored on the CD can be divided into two types. One is music or graphics data that has low accuracy requirements and can tolerate some Byte errors. The other is computers that have very strict accuracy requirements. Numerical or literal data is not allowed to contain erroneous bit data.
The book defines two different types of data structures: Mode-1 and Mode-2. In the header field of the CD-ROM sector (Sector), it contains instructions for this area. The internal data is Byte of Mode-1 or Mode-2. Mode-1 means that the CD-ROM data contains error correction code (288Bytes), and each sector stores 2048Bytes of data. Mode-2 data cancels error correction codes and saves space. Therefore, each sector can store 288Bytes more, with a total of 2336Bytes. Therefore, Mode-2 is more suitable for storing graphics, sound or audio and video data.
When converted into computer data unit Byte, the conversion formula is as follows:
Mode-1: (650MBytes)=74 minutes 2: (742MBytes)=74 minutes format to store data. Most CD-ROM computer optical discs, including programs, computer games, encyclopedias or free software, use Mode-1 to store data. Other optical discs, such as Photo CD, CD-I and Video CD, are stored in Mode-2.
CD-ROM has powerful functions and reasonable price. It is ideal for storing graphics, digital video signals and sound files. The disc itself is well protected and is not easily affected by scratches and dust. , but it cannot be read and written at will like ordinary magnetic disks and hard drives. On CD-ROM discs, data cannot be deleted and rewritten at will. Therefore, not long after the success of CD laser music discs, CD data discs used in computers were also developed, called CD-ROM. ROM stands for Read Only Memory, and music data was converted into computer data. The data is actually not complicated, because data is mainly stored digitally on CDs, and computer signals are processed digitally (0 or 1).
The application of CD-ROM in multimedia was originally for the owners of huge data, such as book data, reference systems or parts manuals. According to statistics in 1992, 60% of all CD-ROM TITLEs are mainly text data. However, with the popularity of multimedia, many optical discs are now designed for applications including: agriculture, books, commerce, medicine , Directory, Education, Encyclopedia, Entertainment, Graphics, Health Care, History, Leisure, Literature, Lifestyle, Music and Sound Effects, Research Science and Technology, etc.
3. Green Paper
The Green Paper defines the specifications of CD-I (Compact Disc Interactive), referred to as interactive disc. The only standard in all specifications that includes hardware specifications, including CPU, operating system, memory, Video and Audio controllers, and audio and video data compression methods.
CD-I is defined as a consumer electronic product, that is, a product with functions similar to TVs, VCRs, etc. It can be directly connected to a TV and controlled by a remote control. It does not have software Floppy and Hard Disk completely use optical drives as data input devices and use real-time operating systems.
4. Orange Book
The standard format defined by the Orange Book (CD-Recordable), referred to as recordable disc. It can be divided into three categories: CD-MO (part I), CD-R (part II), and CD-RW (part III). CD-MO has withdrawn from market demand before it can be popularized. Therefore, CD-R and CD-RW is the most widely used storage media today.
CD-R recordable optical disc:
Can write data on the optical disc once, and must be equipped with a CD-R optical disc writer and burning software to perform writing. The action can write computer data or music, but the written data is not easy to change and delete, and it has high security for data preservation. The world's first CD-R film was designed by Japan's Taiyo Yuden. Later, Japan's Mitsui Chemicals and Japan's Mitsubishi Chemical successively invested in the development of new dyes, and derived dye materials for various types of CD-Rs, targeting different reading and writing abilities and Strengthen light resistance, moisture resistance, and durability and make improvements to create a more perfect recording media.
CD-RW rewritable disc:
The data on the disc can be rewritten and erased. A CD-RW disc burner and specialized burning software are required to perform this operation. The write-erase action allows the data on the disc to be freely changed and deleted, and its service life can reach a thousand times. Compared with CD-R, its usage flexibility is greater. CD-RW is a good choice for data with large fluctuations. .
5. White Paper
The white paper defines the standard format of (VIDEO-CD), referred to as laser video disc. The video quality is equivalent to S-VHS video quality, and the playback sound effect can reach the stereo sampling frequency (44.1KHz, 16bits). It can be played dynamically in full screen, and the playback time is about 74 minutes. An interactive menu function is added, so you can choose to play at will. Clips use MPEG-1 technology to digitize audio and video and store movies on CDs.
VIDEO-CD contains MPEG, which is a special full-motion video format. To play the video, you must be equipped with an MPC3 or above computer, a CD-I player or a laser disc player.
Nowadays, VIDEO-CD on the market emphasizes the functions of Version 2.0, which includes the interactive menu PBC (Play Back Control) function, and Karaoke-CD includes digital music tracks to achieve sound and light. The best state of effect.
6. Blue Book
Blue Book defines the standard format of (Enhanced-CD), referred to as Enhanced CD. This kind of optical disc refers to the characteristics of the two specifications of the Red Book and the Yellow Book. It is a technology derived from the use of music tracks that can be followed by data tracks. It can make the protected data tracks unreadable by ordinary CD music players, but can be read by the computer's optical drive. To the data track and music track, this technology is often used in computer game discs to enable three-dimensional music to run smoothly with the game, allowing you to enjoy the pleasure of computer entertainment.