On the problem of burning optical discs

CD-DA

CD

Burnable optical disc

Rewritable optical disc

laser record

Optical disc XA

Photo disc

video compact disc (VCD)

CD EXTRA

DVD-ROM

DVD-R

DVD-RW

DVD+RW

DVD+RW is the simplest and easiest DVD recording standard, which has the best compatibility with existing formats and is cheap. The DVD+RW standard was jointly formulated by Ricoh, Philips, Sony, Yamaha and other companies, and an industrial organization of DVD+RW alliance was established. DVD+RW is the only rewritable format that is completely compatible with existing DVD players and DVD drives, that is, it is completely compatible with real-time video recording and random data storage in computer and entertainment applications. DVD+RW can not only be used as data storage of PC, but also can directly burn video information in the format of DVD video, which is a great breakthrough in DVD industry. With the development and popularization of DVD+RW, DVD+RW has become a rewritable DVD standard that closely combines DVD video with DVD burner on PC.

Features of DVD+RW:

Single-sided capacity of 4.7GB；; Double-sided capacity 9.4GB

Video with a maximum recording time of 4 hours on one side; 8 hours each.

The laser wavelength is 650 nm, which is the same as DVD video.

Data density at constant linear velocity

CLV and CAV combustion

UDF (universal disk format) file system

Quick format

Sequential combustion or random combustion

Lossless link (multiple records will not waste disk space)

After firing, all physical parameters conform to DVD-ROM specifications.

DVD+RW has the ease of use of DVD-RAM optical drive, which improves the compatibility of DVD-RW optical drive. Although the formatting time of DVD+RW takes about one hour, it can be formatted in the background from the middle, and the data can be burned in one minute. It is the fastest practical DVD burner at present. . At the same time, DVD+R/RW standard is the only DVD recording standard supported by Microsoft.

DVD-RW standard was put forward by Pioneer Company in 1998, and was strongly supported by DVD forum. Its members include Apple, Hitachi, NEC, Samsung and Panasonic, and the official standard 1. 1 was completed in the middle of 2000. DVD-RW products were originally located in consumer electronics products, which mainly provided functions similar to VHS video tapes, and could record high-quality multimedia video information for consumers. But with the development of technology, the function of DVD-RW has gradually extended to the computer field. The principle of DVD-RW recording is similar to that of ordinary CD-RW recording, and it also adopts the phase-change reading and writing technology, which is also a fixed linear speed CLV recording method.

The advantage of DVD-RW is its good compatibility. It can save data in DVD video format, so it can be played on DVD player. However, one of its great disadvantages is that it takes one and a half hours to format. In addition, DVD-RW provides two recording modes: one is called video recording mode; The other is called DVD video mode. The former mode is rich in functions, but it is not compatible with DVD players. Users need to choose between these two formats, which is not very convenient to use.

DVD-R is a write-once medium similar to CD-R, which is very suitable for recording archive data. DVD-R discs can be played on standard DVD-ROM drives.

The single-sided capacity of DVD-R is 3.95GB, which is about 6 times that of CD-R, and the capacity of double-sided disk is twice as large. This kind of optical disc uses a layer of organic fuel to burn, thus reducing the material cost.

DVD-RAM is a writable DVD standard jointly launched by Pioneer, Hitachi and Toshiba, which adopts a technology similar to CD-RW. However, due to the difference of medium reflectivity and data format, most standard DVD-ROM drives cannot read DVD-RAM disks. DVD-ROM drives that can read DVD-RAM disks first appeared in the early days of 1999, and DVD-Roms and DVD players that meet the Multi-Read 2 standard can read DVD-RAM disks.

The first DVD-RAM optical drive was launched in the spring of 1998, with a capacity of 2.6GB (single-sided) and 5.2GB (double-sided). The 4.7GB disk came out at the end of 1999, and the double-sided 9.4GB disk was put on the market in 2000. The DVD-RAM drive can read DVD video, DVD-ROM and CD.

CD-DA media manufacturers have been looking for a specification that can store music and data on CDs. Users can play audio on the CD player, but the data stored on the CD will not affect the normal playback of the CD player. And both can be accessed simultaneously on a PC. The key to solve this problem is that although the CD track and the data track can be different, when the CD player tries to play the data track, it will inevitably emit electrostatic noise. 1995 Phlips and Sony developed the CD EXTRA specification, which is the blue book standard. Multi-section technology is defined in the CD EXTRA standard to separate audio and data tracks. The audio part of a CD can contain as many as 98 standard red book audio tracks, while the data tracks generally consist of XA mode 2 sectors, which can contain videos, songs, lyrics, still pictures or other multimedia information. CD EXTRA is mostly made into audio CD by CD media manufacturers, which includes data files such as lyrics, videos, singer information and pictures.

Video CD was released by Phlips, JVC, Panasonic and Sony on 1993. Its standard is also called "white paper". Based on the standards of CD-I and CD-ROM XA, it is allowed to store MPEG- 1 video and ADPCM digital audio data for 74 minutes on one optical disc. It can be played by Microsoft's media player on a personal computer with a CD-ROM drive. With the popularity of DVD discs, such products will gradually withdraw from the historical stage.

The photo CD first appeared in 1990 and was not officially released until 1992. It is a CD-R disc and drive standard for storing pictures, mainly developed by Kodak. As long as users send the film to the corresponding Kodak outlets, they will digitally store the film in CD-R discs in photo disc format. Of course, this is only possible for extremely professional photography, and its expensive price far exceeds the acceptance ability of ordinary users.

The images on the photo CD are compressed and stored in Kodak's own PhotoYCC encoding format, and each image has up to 6 different resolutions.

CD-ROM XA was originally developed by Phlips, Sony and Microsoft as a supplement to 1989 Yellow Book (CD-ROM). It introduces some features of the Green Book (CD-I) into CD-ROM, especially in multimedia. CD-ROM XA has added three main features to the Yellow Book standard: the first feature is to improve the sector definition of mode 2 sector and introduce the formal concept of CD-I; The second feature is the introduction of a function called interleaving (mixing audio and video information); The third feature is to use ADPCM to compress audio information.

The CD-I specification was issued by Philips and Sony in 1986, which is the standard of the Green Paper. CD-I is not only a format, but also a complete specification of the whole interactive system. CD-I player is actually a special kind of computer. The CD-I standard allows audio and video data to be stored on the same optical disc at the same time, and these data can be stored alternately to keep the synchronization of images and sounds.

The Yellow Book defines two structures of optical disc, namely mode 1 and mode 2. The Green Book (CD-I) added two tables to Mode 2, namely Mode 2, Table 1 and Mode 2, Table 2, which further improved Mode 2 in the Yellow Book. Mode 2 and mode 1 use 2048 bytes of data storage, similar to ECC and yellow book mode 1, but slightly modified. Mode 2 and Form 2 do not provide ECC and can store 2324 bytes of data. Because ECC is not supported, the sectors in Table 2 can only store information such as video and audio that can tolerate minor errors.

CD-I can store educational and training programs, games, encyclopedias, karaoke and movies. It should be pointed out that CD-I cannot be played on a PC. In fact, because the files are stored in OS/9 format, the PC can't view the files on the CD at all. However, you can view such files by installing some special drivers. Another company has written a CD-I emulator called CD-ICE, so that you can run CD-I applications.

Nowadays, the CD-I format is out of date and has basically disappeared from the market.

At the beginning of 1996, Ricoh, Philips, Sony, Yamaha, Hewlett-Packard and Mitsubishi Chemical Company set up an industrial forum and released the CD-RW format standard. The standard was formulated by Ricoh, and in 1996, the industry's first CD-RW optical drive model MP6200S was introduced, which is a product with twice the recording speed, twice the copying speed and six times the reading speed. At the same time, the third part of the orange book was officially published, which officially defined the CD-RW standard.

Since then, CD-RW drive has replaced CD-R drive, which is fully compatible with CD-R drive and fully supports CD-R discs. CD-rw discs are burned in the same way as CD-RW discs, but the difference is that they can be erased and rewritten many times. In this way, the CD-RW disk can be regarded as a floppy disk, and files can be copied and deleted, which is convenient and flexible.

There are four main differences between CD-RW and CD-R:

Rewritable

Higher price

Slow writing speed

The reflectivity is low.

The writing speed of CD-RW disk is lower than that of CD-R disk, because the laser needs more time to operate the disk when writing data. Unlike the organic dye layer of CD-R, the recording layer of CD-RW disk is composed of silver, indium, antimony and tellurium alloys. The combustion layer of the alloy has polycrystalline structure and emissivity is about 20%. The laser head of CD-RW drive has two wavelength settings, namely P-Write and P-erase. During recording, the laser heats the material in the recording layer to 500 ~ 700 degrees Celsius to melt it. In the liquid state, the molecules of the substance move freely, and the polycrystalline structure changes, showing an amorphous state (immediate state). However, the reflectivity of the cured recording layer material in this state is only 5%, and these places with low reflectivity are equivalent to "depressions" on the optical disk.

The above method is the process of writing data in CD-RW, and to erase data, the material in the recording layer must be restored to polycrystalline structure. At this time, the laser head adopts a low-energy erasing state, and the recording layer material is heated to 200 degrees Celsius, which will not melt, but will soften. When the recording layer material softens and cools slowly, its molecular structure will change from amorphous structure with 5% reflectivity to polycrystalline structure with 20% reflectivity. It returns to the initial state of the CD-RW disc.

In practical work, the CD-RW drive does not erase all data contents before recording data, but directly rewrites where data is to be written. In other words, when recording data, the laser head can switch between writing and erasing states at any time and make adjustments as needed.

1989, Phlips and Sony released the orange book with recordable CD standard, which contains three parts: the first part 1 is CD-MO (magneto-optical) standard, which is a rewritable recording standard, but this standard was quickly cancelled, and even no products with this standard came out. The second part formulates the CD-R standard; The third part establishes the CD-RW standard.

CD-R is a write-once and read-forever standard. After data is written to CD-R, it can't be written again. The burned CD can be read on CD-DA or CD-ROM drive. The working principle of CD-R is the same as that of CD-R, and it is read by the changes of reflected light from "pits" and "flats" irradiated by laser. The difference is that the "depression" of CD=ROM is printed, while the CD-R burner is fired.

Due to different products and production lines, different dyes are used in the reflective layer of CD-R products, commonly known as "golden disc", "green disc" and "blue disc". Their colors and properties are different, and each has its own advantages.

CD-ROM, also known as CD-ROM, is a read-only optical storage medium. It was developed by using the CD-DA (Digital Audio) format originally used for audio CDs. Other formats, such as CD-R (CD-R recordable) and CD-RW (CD-R writable), increase the writeability of optical discs. For a long time, optical drive has been considered as the standard equipment of most PCs.

The yellow book of CD specifications was introduced by Philips, Sony and Microsoft in 1983, and has been revised many times. The Yellow Book adopts the physical format of CD-DA (Red Book) and adds a layer of error detection and correction standards to ensure the reliability of data storage. In addition, synchronization and marking information are added to achieve more accurate positioning. The Yellow Book provides two modes and different error detection and correction mechanisms, because stored data documents (computer files) are not allowed to have errors, while video images, sounds and other data are allowed to have a small number of errors. 1989, the Yellow Book was accepted by ISO as the international standard for data exchange of 120mm optical discs-ISO/IEC10/49.

CD is a read-only optical storage medium, which can store 74-80 minutes or 682MB(74 minutes) /737MB(80 minutes) of high-definition audio on a single-sided CD with a diameter of 120mm(4.72 inches) and a thickness of 1.2mm(0.047 inches). CD-ROM has the same shape as ordinary CD, but it stores data instead of audio. A CD-ROM drive in a PC reads data in a way similar to a CD player. The main difference is that the inspection and error correction mechanism is introduced into the optical disk drive circuit to ensure that there will be no errors when reading data.

CD-ROM is made of carbonate and has a hole with a diameter of 15mm in the center. A spiral physical track is cast on the disk base, which spirals from the inside of the disk to the outermost ring. Etched pits are arranged inside the track, and these pits and lands constitute the stored data information. Because the laser reading the optical disc will pass through the plastic layer, it is necessary to cover it with a metal reflective layer (usually aluminum alloy) to reflect the light, and then cover it with a protective layer of acrylic acid. It should be noted that when the surface of the optical drive is dirty and scratched, its readability will be reduced. Although the CD is read from below, try to avoid using hard pens such as ballpoint pens to write on the front of the CD, which is easy to scratch the data layer below the protective layer.

From 65438 to 0979, Philips and Sony formed an alliance to jointly develop the CD-DA standard. Philips has developed a commercial CD player, while Sony has more than ten years of research experience in digital recording technology. When they agreed to standardize a single audio technology, the two companies got into a quarrel-this introduced a potentially incompatible audio laser disc format.

Phlipis mainly carries out physical design. The optical disc designed by it is similar to the laser disc produced before, and the pits and lands on the optical disc can be read by laser. Sony mainly designs digital-analog circuits, especially digital coding and error-correcting codes.

1980, the two companies released the CD-DA standard, which is today's red book standard (named after the red cover of the release document). The red book includes the specifications of recording and collection, and the physical format of 120mm(4.72 inches) still in use today. It is said that the size of this CD is because it can accommodate all the contents of Beethoven's Ninth Symphony without interruption for about 70 minutes.

After the release of the specification, the two companies competed to launch the first commercial CD audio driver. Because Sony has rich experience in digital circuits, it finally won after competing with Phlipis for a month, and released CDP-10/0/player and ——Billy Joe's 52nd Street album on June 1982 10, the world's first CD. The player was first listed in Japan, then in Europe, and did not enter the American market until the beginning of 1983. 1984, Sony introduced the first portable CD player.