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CD
The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in October 1982 in Japan and branded as '' Digital Audio Compact Disc''. The format was later adapted (as CD-ROM) for general-purpose data storage. Several other formats were further derived, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video CD (VCD), Super Video CD (SVCD), Photo CD, Picture CD, Compact Disc-Interactive (CD-i) and Enhanced Music CD. Standard CDs have a diameter of and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650 MiB of data. Capacity is routinely extended to 80 minutes and 700 MiB by arranging data more closely on the same sized disc. The Mini CD has various diameters ranging from ; they are sometimes used for CD singles, storing up to 24 minu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD-i
The Compact Disc-Interactive (CD-I, later CD-i) is a digital optical disc data storage format that was mostly developed and marketed by Dutch company Philips. It was created as an extension of CDDA and CD-ROM and specified in the '' Green Book'', co-developed by Philips and Sony, to combine audio, text and graphics. The two companies initially expected to impact the education/training, point of sale, and home entertainment industries, but CD-i eventually became best known for its video games. CD-i media physically have the same dimensions as CD, but with up to of digital data storage, including up to 72 minutes of full motion video. CD-i players were usually standalone boxes that connect to a standard television; some less common setups included integrated CD-i television sets and expansion modules for personal computers. Most players were created by Philips; the format was licensed by Philips and Microware for use by other manufacturers, notably Sony who released professiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD-RW
CD-RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sensitive laser optics. Consequently, CD-RWs cannot be read in many CD readers built prior to the introduction of CD-RW. CD-ROM drives with a "MultiRead" certification are compatible. CD-RWs must be erased or blanked before reuse. Erasure methods include full blanking where the entire surface of the disc is erased and fast blanking where only metadata areas, such as PMA, TOC and pregap, are cleared. Fast blanking is quicker and usually sufficient to allow rewriting the disc. Full blanking removes all traces of the previous data, and is often used for confidentiality purposes. CD-RWs can sustain fewer re-writes compared to other storage media (ca. 1,000 compared up to 100,000). Ideal use is for test discs (e.g. for CD authoring), temporary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD-R
CD-R (Compact disc-recordable) is a digital optical disc storage format. A CD-R disc is a compact disc that can be written once and read arbitrarily many times. CD-R discs (CD-Rs) are readable by most CD readers manufactured prior to the introduction of CD-R, unlike CD-RW discs. History Originally named CD Write-Once (WO), the CD-R specification was first published in 1988 by Philips and Sony in the Orange Book, which consists of several parts that provide details of the CD-WO, CD-MO (Magneto-Optic), and later CD-RW (ReWritable). The latest editions have abandoned the use of the term "CD-WO" in favor of "CD-R", while " CD-MO" was rarely used. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the audio CD (''Red Book'' CD-DA) and data CD (''Yellow Book'' CD-ROM) standards. The Yellow Book standard for CD-ROM only specifies a high-level data format and refers to the Red Book for all physical format and low-level code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Disc
In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. Its main uses are physical offline data distribution and long-term archival. Changes from pit to land or from land to pit correspond to a binary value of 1; while no change, regardless of whether in a land or a pit area, corresponds to a binary value of 0. Non-circular optical discs exist for fashion purposes; see shaped compact disc. Design and technology The encoding material sits atop a thicker substrate (usually polycarbonate) that makes up the bulk of the disc and forms a dust defocusing layer. The encoding pattern follows a continuous, spiral path covering the entire disc surface and extending from the innermost track to the outermost track. The data are stored on the disc with a laser or stamping machine, and can be accessed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compact Disc Digital Audio
Compact Disc Digital Audio (CDDA or CD-DA), also known as Digital Audio Compact Disc or simply as Audio CD, is the standard format for audio compact discs. The standard is defined in the ''Red Book'', one of a series of Rainbow Books (named for their binding colors) that contain the technical specifications for all CD formats. The first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan. The format gained worldwide acceptance in 1983–84, selling more than a million CD players in those two years, to play 22.5 million discs. Beginning in the 2000s, CDs were increasingly being replaced by other forms of digital storage and distribution, with the result that by 2010 the number of audio CDs being sold in the U.S. had dropped about 50% from their peak; however, they remained one of the primary distribution methods for the music industry. In the 2010s, revenues from digital music services, such as iTunes, Spotify, and YouTube, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video CD
Video CD (abbreviated as VCD, and also known as Compact Disc Digital Video) is a home video format and the first format for distributing films on standard optical discs. The format was widely adopted in Southeast Asia, Central Asia and the Middle East, superseding the VHS and Betamax systems in the regions until DVD-Video finally became affordable in the first decade of the 21st century. The format is a standard digital data format for storing video on a compact disc. VCDs are playable in dedicated VCD players and widely playable in most DVD players, personal computers and some video game consoles. However, they are less playable in most Blu-ray Disc players, vehicle audio with DVD/Blu-ray support and video game consoles such as the Sony PlayStation and Xbox due to lack of backward compatibility for the older MPEG-1 format, inability to read MPEG-1 in .dat files alongside MPEG-1 in standard MPEG-1, AVI, and Matroska files, or inability to read CD-ROM XA discs. Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photo CD
Photo CD is a system designed by Kodak for digitizing and saving photos onto a CD. Launched in 1991, the discs were designed to hold nearly 100 high quality images, scanned prints and slides using special proprietary encoding. Photo CDs are defined in the Beige Book and conform to the CD-ROM XA and CD-i Bridge specifications as well. They were intended to play on CD-i players, Photo CD players ( Apple's PowerCD for example), and any computer with a suitable software ( LaserSoft Imaging's SilverFast DC or HDR for example). The system failed to gain mass usage among consumers partly due to its proprietary nature, the rapidly decreasing scanner prices, and the lack of CD-ROM drives in most home personal computers of the day. Furthermore, Photo CD relied on CRT-based TV sets for home use. However, these were designed for moving pictures. Their typical flicker became an issue when watching still photographs. The Photo CD system gained a fair level of acceptance among profes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffraction Grating
In optics, a diffraction grating is an optical component with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction angles). The emerging coloration is a form of structural coloration. The directions or diffraction angles of these beams depend on the wave (light) incident angle to the diffraction grating, the spacing or distance between adjacent diffracting elements (e.g., parallel slits for a transmission grating) on the grating, and the wavelength of the incident light. The grating acts as a dispersive element. Because of this, diffraction gratings are commonly used in monochromators and spectrometers, but other applications are also possible such as optical encoders for high precision motion control and wavefront measurement. For typical applications, a reflective grating has ridges or ''rulings'' on its surface while a transmissive grating has transmissive or hollow slits on its surface. Such a gratin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereo
Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration of two loudspeakers (or stereo headphones) in such a way as to create the impression of sound heard from various directions, as in natural hearing. Because the multi-dimensional perspective is the crucial aspect, the term ''stereophonic'' also applies to systems with more than two channels or speakers such as quadraphonic and surround sound. Binaural sound systems are also ''stereophonic''. Stereo sound has been in common use since the 1970s in entertainment media such as broadcast radio, recorded music, television, video cameras, cinema, computer audio, and internet. Etymology The word ''stereophonic'' derives from the Greek (''stereós'', "firm, solid") + (''phōnḗ'', "sound, tone, voice") and it was coined in 1927 by Western E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhanced Music CD
The Blue Book is a compact disc standard developed in 1995 by Philips and Sony. It defines the Enhanced Music CD format (E-CD, also known as CD-Extra, CD-Plus and CD+), which combines audio tracks and data tracks on the same disc. The format was created as a way to solve the problem of mixed mode CDs, which were not properly supported by many CD players. E-CDs are created through the ''stamped multisession'' technology, which creates two sessions on a disc. The first session of an E-CD contains audio tracks according to the Red Book. As a consequence, existing compact disc players can play back this first session as an audio disc. The second session contains CD-ROM data files with content often related to the audio tracks in the first session. The second session will only be used by computer systems equipped with a CD-ROM drive, or by special “Enhanced CD players”. The second session of a E-CD contains one track in CD-ROM XA Mode 2, Form 1 format. It must contain certai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mini CD
Mini CDs, or pocket CDs, are CDs with a smaller diameter and one-third the storage capacity of a standard 120 mm disc. Formats Amongst the various formats are the * Mini CD single, a small disc. The format is mainly used for audio CD singles in certain regions (singles are sold on normal 120 mm CDs in many countries), much like the old vinyl single. An 80 mm disc can hold up to 24 minutes of music, or 210 MiB (210 × 220 bytes) of data. They are often referred to as ''Maxi CDs'' in some countries. **The low density version holds 18 minutes, or 155 MB. **Other formats are 185 MB (21 mins), which has the same data density as a 650 MB full-sized CD, and 210 MB (24 mins), with the same data density as a 700 MB full-sized CD, used for "Pocket" data storage. (see also miniDVD) *Business card CD (or "b-card"), a truncated (to the shape and size of a business card) disc with a storage capacity from 30 MB ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
