Lossless Transform Audio Compression
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Lossless Transform Audio Compression
Lossless Transform Audio Compression (LTAC) is a compression algorithm developed by Tilman Liebchen, Marcus Purat and Peter Noll at Institute for Telecommunications, Technical University Berlin (TU Berlin), to compress PCM audio in a lossless manner, ''unlike'' conventional lossy audio compression algorithms (like MP3). LTAC will not be developed any further since it has been superseded by its successor Lossless Predictive Audio Compression (LPAC), which is based on linear prediction. This makes it much faster than LTAC and even leads to better compression results. LPAC has become official standard as MPEG-4 Audio Lossless Coding MPEG-4 Audio Lossless Coding, also known as MPEG-4 ALS, is an extension to the MPEG-4 Part 3 audio standard to allow lossless audio compression. The extension was finalized in December 2005 and published as ISO/IEC 14496-3:2005/Amd 2:2006 in 2006. .... See also * Lossless Predictive Audio Compression (LPAC) References External links Lossle ...
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Audio Data Compression
In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as a decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission, it is called source coding; encoding done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding, for error detection and correction or line coding, the means for mapping data onto a signal. C ...
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Tilman Liebchen
Tilman is both a masculine given name and a surname. The German version of the surname is Tillmann. Other variants include Tillman and Dillman. Notable people with the name include: People with the given name * Tilman Fertitta (1957), American businessman * Tilman Goins, Tennessee State Lower House Chamber Member from Hamblen County * Tilman Bacon Parks (1872–1950), U.S. Representative from Arkansas * Tilman Pesch (1836–1899), German Jesuit philosopher * Tilman Riemenschneider (1460–1531), German sculptor and woodcarver * Tilman Valentin "Til" Schweiger (born 1963), German actor, director, and producer * Saint Tilman (c. 608–702), French priest, abbot and hermit People with the surname * Bill Tilman (1898–1977), English mountaineer and explorer * G. David Tilman (born 1949), American ecologist * Felicia Tilman, fictional character in the television series ''Desperate Housewives'' * Manuel Tilman, East Timorese politician * Pat Tillman (1976–2004), American foo ...
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Marcus Purat
Marcus, Markus, Márkus or Mărcuș may refer to: * Marcus (name), a masculine given name * Marcus (praenomen), a Roman personal name Places * Marcus, a main belt asteroid, also known as (369088) Marcus 2008 GG44 * Mărcuş, a village in Dobârlău Commune, Covasna County, Romania * Marcus, Illinois, an unincorporated community * Marcus, Iowa, a city * Marcus, South Dakota, an unincorporated community * Marcus, Washington, a town * Marcus Island, Japan, also known as Minami-Tori-shima * Mărcuș River, Romania * Marcus Township, Cherokee County, Iowa Other uses * Markus, a beetle genus in family Cantharidae * ''Marcus'' (album), 2008 album by Marcus Miller * Marcus (comedian), finalist on ''Last Comic Standing'' season 6 * Marcus Amphitheater, Milwaukee, Wisconsin * Marcus Center, Milwaukee, Wisconsin * Marcus & Co., American jewelry retailer * Marcus by Goldman Sachs, an online bank * USS ''Marcus'' (DD-321), a US Navy destroyer (1919-1935) See also * Marcos (disambiguation ...
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Peter Noll
Peter may refer to: People * List of people named Peter, a list of people and fictional characters with the given name * Peter (given name) ** Saint Peter (died 60s), apostle of Jesus, leader of the early Christian Church * Peter (surname), a surname (including a list of people with the name) Culture * Peter (actor) (born 1952), stage name Shinnosuke Ikehata, Japanese dancer and actor * ''Peter'' (album), a 1993 EP by Canadian band Eric's Trip * ''Peter'' (1934 film), a 1934 film directed by Henry Koster * ''Peter'' (2021 film), Marathi language film * "Peter" (''Fringe'' episode), an episode of the television series ''Fringe'' * ''Peter'' (novel), a 1908 book by Francis Hopkinson Smith * "Peter" (short story), an 1892 short story by Willa Cather Animals * Peter, the Lord's cat, cat at Lord's Cricket Ground in London * Peter (chief mouser), Chief Mouser between 1929 and 1946 * Peter II (cat), Chief Mouser between 1946 and 1947 * Peter III (cat), Chief Mouser between 1947 a ...
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Berlin
Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constituent states, Berlin is surrounded by the State of Brandenburg and contiguous with Potsdam, Brandenburg's capital. Berlin's urban area, which has a population of around 4.5 million, is the second most populous urban area in Germany after the Ruhr. The Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's third-largest metropolitan region after the Rhine-Ruhr and Rhine-Main regions. Berlin straddles the banks of the Spree, which flows into the Havel (a tributary of the Elbe) in the western borough of Spandau. Among the city's main topographical features are the many lakes in the western and southeastern boroughs formed by the Spree, Havel and Dahme, the largest of which is Lake Müggelsee. Due to its l ...
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TU Berlin
The Technical University of Berlin (official name both in English and german: link=no, Technische Universität Berlin, also known as TU Berlin and Berlin Institute of Technology) is a public research university located in Berlin, Germany. It was the first German university to adopt the name "Technische Universität" (Technical University). The university alumni and professor list includes several US National Academies members, two National Medal of Science laureates and ten Nobel Prize laureates. TU Berlin is a member of TU9, an incorporated society of the largest and most notable German institutes of technology and of the Top International Managers in Engineering network, which allows for student exchanges between leading engineering schools. It belongs to the Conference of European Schools for Advanced Engineering Education and Research. The TU Berlin is home of two innovation centers designated by the European Institute of Innovation and Technology. The university is labeled ...
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Pulse-code Modulation
Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled regularly at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps. Linear pulse-code modulation (LPCM) is a specific type of PCM in which the quantization levels are linearly uniform. This is in contrast to PCM encodings in which quantization levels vary as a function of amplitude (as with the A-law algorithm or the μ-law algorithm). Though ''PCM'' is a more general term, it is often used to describe data encoded as LPCM. A PCM stream has two basic properties that determine the stream's fidelity to the original analog signal: the sampling rate, which is the number of times per second that samples are taken; and the bit depth, which determines the ...
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Lossless Compression
Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statistical redundancy. By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved compression rates (and therefore reduced media sizes). By operation of the pigeonhole principle, no lossless compression algorithm can efficiently compress all possible data. For this reason, many different algorithms exist that are designed either with a specific type of input data in mind or with specific assumptions about what kinds of redundancy the uncompressed data are likely to contain. Therefore, compression ratios tend to be stronger on human- and machine-readable documents and code in comparison to entropic binary data (random bytes). Lossless data compression is used in many ...
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Lossy Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression al ...
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Linear Prediction
Linear prediction is a mathematical operation where future values of a discrete-time signal are estimated as a linear function of previous samples. In digital signal processing, linear prediction is often called linear predictive coding (LPC) and can thus be viewed as a subset of filter theory. In system analysis, a subfield of mathematics, linear prediction can be viewed as a part of mathematical modelling or optimization. The prediction model The most common representation is :\widehat(n) = \sum_^p a_i x(n-i)\, where \widehat(n) is the predicted signal value, x(n-i) the previous observed values, with p \leq n , and a_i the predictor coefficients. The error generated by this estimate is :e(n) = x(n) - \widehat(n)\, where x(n) is the true signal value. These equations are valid for all types of (one-dimensional) linear prediction. The differences are found in the way the predictor coefficients a_i are chosen. For multi-dimensional signals the error metric is often defined ...
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Audio Lossless Coding
MPEG-4 Audio Lossless Coding, also known as MPEG-4 ALS, is an extension to the MPEG-4 Part 3 audio standard to allow lossless audio compression. The extension was finalized in December 2005 and published as ISO/IEC 14496-3:2005/Amd 2:2006 in 2006. The latest description of MPEG-4 ALS was published as subpart 11 of the MPEG-4 Audio standard (ISO/IEC 14496-3:2019) (5th edition) in December 2019. MPEG-4 ALS combines a short-term predictor and a long term predictor. The short-term predictor is similar to FLAC in its operation - it is a quantized LPC predictor with a losslessly coded residual using Golomb Rice Coding or Block Gilbert Moore Coding (BGMC). The long term predictor is modeled by 5 long-term weighted residues, each with its own lag (delay). The lag can be hundreds of samples. This predictor improves the compression for sounds with rich harmonics (containing multiples of a single fundamental frequency, locked in phase) present in many musical instruments and human voice. ...
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