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Super Bit Mapping
Super Bit Mapping (SBM) is a noise shaping process, developed by Sony for CD mastering. Sony claims that the Super Bit Mapping process converts a 20-bit signal from master recording into a 16-bit signal nearly without sound quality loss, using noise shaping to improve signal-to-noise ratio over the frequency bands most acutely perceived by human hearing. Audible quantization error is reduced by noise shaping the error according to an equal-loudness contour. This processing takes place in dedicated hardware inside the recording device. A similar process is used in Sony's DSD to PCM conversion and is called ''SBM Direct''. See also * Extended Resolution Compact Disc (XRCD) * High Definition Compatible Digital High Definition Compatible Digital (HDCD) is a proprietary audio encode-decode process that claims to provide increased dynamic range over that of standard Compact Disc Digital Audio, while retaining backward compatibility with existing compact d ... (HDCD) Refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super Bit Mapping (SBM) Logo
Super Bit Mapping (SBM) is a noise shaping process, developed by Sony for CD mastering. Sony claims that the Super Bit Mapping process converts a 20-bit signal from master recording into a 16-bit signal nearly without sound quality loss, using noise shaping to improve signal-to-noise ratio over the frequency bands most acutely perceived by human hearing. Audible quantization error is reduced by noise shaping the error according to an equal-loudness contour. This processing takes place in dedicated hardware inside the recording device. A similar process is used in Sony's DSD to PCM conversion and is called ''SBM Direct''. See also * Extended Resolution Compact Disc (XRCD) * High Definition Compatible Digital High Definition Compatible Digital (HDCD) is a proprietary audio encode-decode process that claims to provide increased dynamic range over that of standard Compact Disc Digital Audio, while retaining backward compatibility with existing compact d ... (HDCD) Refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise Shaping
Noise shaping is a technique typically used in digital audio, image, and video processing, usually in combination with dithering, as part of the process of quantization or bit-depth reduction of a digital signal. Its purpose is to increase the apparent signal-to-noise ratio of the resultant signal. It does this by altering the spectral shape of the error that is introduced by dithering and quantization; such that the noise power is at a lower level in frequency bands at which noise is considered to be less desirable and at a correspondingly higher level in bands where it is considered to be more desirable. A popular noise shaping algorithm used in image processing is known as ‘ Floyd Steinberg dithering’; and many noise shaping algorithms used in audio processing are based on an ‘Absolute threshold of hearing’ model. Operation Noise shaping works by putting the quantization error in a feedback loop. Any feedback loop functions as a filter, so by creating a feedback l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional electronic products, the largest video game console company and the largest video game publisher. Through Sony Entertainment Inc, it is one of the largest music companies (largest music publisher and second largest record label) and the third largest film studio, making it one of the most comprehensive media companies. It is the largest technology and media conglomerate in Japan. It is also recognized as the most cash-rich Japanese company, with net cash reserves of ¥2 trillion. Sony, with its 55 percent market share in the image sensor market, is the largest manufacturer of image sensors, the second largest camera manufacturer, and is among the semiconductor sales leaders. It is the world's largest player in the premium TV market for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compact Disc
The compact disc (CD) is a Digital media, 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 ''Compact Disc Digital Audio, 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 mebibyte, MiB of data. Capacity is routinely extended to 80 minutes and 700 mebibyte, MiB by arranging data more closely on the same sized disc. The Mini CD has various diameters ranging from ; t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Mastering
Mastering, a form of audio post production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device (the master), the source from which all copies will be produced (via methods such as pressing, duplication or replication). In recent years digital masters have become usual, although analog masters—such as audio tapes—are still being used by the manufacturing industry, particularly by a few engineers who specialize in analog mastering. Mastering requires critical listening; however, software tools exist to facilitate the process. Results depend upon the intent of the engineer, the skills of the engineer, the accuracy of the speaker monitors, and the listening environment. Mastering engineers often apply equalization and dynamic range compression in order to optimize sound translation on all playback systems. It is standard practice to make a copy of a master recording—known as a safety copy—in cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Mastering
Mastering, a form of audio post production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device (the master), the source from which all copies will be produced (via methods such as pressing, duplication or replication). In recent years digital masters have become usual, although analog masters—such as audio tapes—are still being used by the manufacturing industry, particularly by a few engineers who specialize in analog mastering. Mastering requires critical listening; however, software tools exist to facilitate the process. Results depend upon the intent of the engineer, the skills of the engineer, the accuracy of the speaker monitors, and the listening environment. Mastering engineers often apply equalization and dynamic range compression in order to optimize sound translation on all playback systems. It is standard practice to make a copy of a master recording—known as a safety copy—in cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal-to-noise Ratio
Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels. A ratio higher than 1:1 (greater than 0 dB) indicates more signal than noise. SNR, bandwidth, and channel capacity of a communication channel are connected by the Shannon–Hartley theorem. Definition Signal-to-noise ratio is defined as the ratio of the power of a signal (meaningful input) to the power of background noise (meaningless or unwanted input): : \mathrm = \frac, where is average power. Both signal and noise power must be measured at the same or equivalent points in a system, and within the same system bandwidth. Depending on whether the signal is a constant () or a random variable (), the signal-to-noise ratio for random noise becomes: : \mathrm = \frac where E refers to the expected value, i.e. in this case ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equal-loudness Contour
An equal-loudness contour is a measure of sound pressure level, over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones. The unit of measurement for loudness levels is the phon and is arrived at by reference to equal-loudness contours. By definition, two sine waves of differing frequencies are said to have equal-loudness level measured in phons if they are perceived as equally loud by the average young person without significant hearing impairment. The Fletcher–Munson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by Harvey Fletcher and Wilden A. Munson, and reported in a 1933 paper entitled "Loudness, its definition, measurement and calculation" in the ''Journal of the Acoustical Society of America''. Fletcher–Munson curves have been superseded and incorporated into newer standards. The definitive curves are those defined in ISO 226 from the International Orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Stream Digital
Direct Stream Digital (DSD) is a trademark used by Sony and Philips for their system for digitally encoding audio signals for the Super Audio CD (SACD). DSD uses pulse-density modulation encoding - a technology to store audio signals on digital storage media which are used for the SACD. The signal is stored as delta-sigma modulated digital audio, which is a sequence of single-bit values at a sampling rate of 2.8224 MHz (64 times the CD audio sampling rate of 44.1 kHz, but only at \tfrac of its 16-bit resolution). Noise shaping occurs by use of the 64-times oversampled signal to reduce noise and distortion caused by the inaccuracy of quantization of the audio signal to a single bit. Therefore, it is a topic of discussion whether it is possible to eliminate distortion in one-bit delta-sigma conversion. Development DSD is a method of storing a delta-sigma signal before applying a decimation process that converts the signal to a PCM signal. Delta-sigma conversion wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extended Resolution Compact Disc
Extended Resolution Compact Disc (XRCD) is a mastering and manufacture process patented by JVC (Victor Company of Japan, Ltd) for producing Red Book compact discs. It was first introduced in 1995. An XRCD is priced about twice as high as a regular full-priced CD. JVC attributes this to the higher cost of quality mastering and manufacturing. Technical overview The XRCD definition refers to the mastering and manufacture process; the resulting CD and the contained data conform to the redbook standard and are encoded at 16 bits, 44.1 kHz. Hence, XRCDs are playable on any compact disc player. JVC uses advanced dither algorithms (though without noise shaping) in their K2 technology to transfer the analog or digital source to physical disc. The company claims to have studied how inferior CD-remastering techniques degrade the master tape sound and strives to minimize this loss. Unlike HDCD, the extra four bits cannot be recovered, as this method of mastering only aims to improve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Definition Compatible Digital
High Definition Compatible Digital (HDCD) is a proprietary audio encode-decode process that claims to provide increased dynamic range over that of standard Compact Disc Digital Audio, while retaining backward compatibility with existing compact disc players. Originally developed by Pacific Microsonics, the first HDCD-enabled CD was released in 1995. In 2000, the technology was purchased by Microsoft, and the following year, there were over 5,000 HDCD titles available. Microsoft's HDCD official website was discontinued in 2005; by 2008, the number of available titles had declined to around 4,000. A number of CD and DVD players include HDCD decoding, and versions 9 and above of Microsoft's Windows Media Player on personal computers are capable of decoding HDCD. HDCD was a favorite for several artists such as Neil Young, the Beach Boys and the Grateful Dead, all of whom have had multiple titles in their catalogs reissued in this format. Technical overview HDCD encodes the equivale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Technology
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges. Acoustics Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an ''acoustician'', while someone working in the field of acoustical e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
