The MP3 lossy data compression algorithm takes advantage of a perceptual limitation of human hearing called In 1894, Mayer reported that a tone could be rendered inaudible by another tone of lower frequency.[2] In 1959, Richard Ehmer described a complete set of auditory curves regarding this phenomenon.[3] Ernst Terhardt et al. created an algorithm describing auditory masking with high accuracy.[4] This work added on a variety of reports from authors dating back to Fletcher, and to the work that initially determined critical ratios and critical bandwidths.The psychoacoustic masking codec was first proposed in 1979, apparently independently, by Manfred R. Schroeder, et al..[5] from AT&T-Bell Labs in Murray Hill, NJ, and M. A.Krasner[6]both in the United States. Krasner was the first to publish and to produce hardware for speech, not usable as music bit compression, but the publication of his results as a relatively obscure Lincoln Laboratory Technical Report did not immediately influence the mainstream of psychoacoustic codec development. Manfred Schroeder was already a well-known and revered figure in the worldwide community of acoustical and electrical engineers, and his paper had influence in acoustic and source-coding (audio data compression) research. Both Krasner and Schroeder built upon the work performed by Eberhard F. Zwicker in the areas of tuning and masking of critical bands,[7][8] that in turn built on the fundamental research in the area from Bell Labs of Harvey Fletcher and his collaborators.[9] A wide variety of (mostly perceptual) audio compression algorithms were reported in IEEE's refereed Journal on Selected Areas in Communications.[10] That journal reported in February 1988 on a wide range of established, working audio bit compression technologies, some of them using auditory masking as part of their fundamental design, and several showing real-time hardware implementations aimed at laboratory experiences. This hardware was never used in PC audio cards.The immediate predecessors of MP3 were "Optimum Coding in the Frequency Domain" (OCF),[11] and Perceptual Transform Coding (PXFM).[12] These two codecs, along with block-switching contributions from Thomson-Brandt, were merged into a codec called ASPEC, which was submitted to MPEG, and which won the quality competition, but that was mistakenly rejected as too complex to implement. The first practical implementation of an audio perceptual coder (OCF) in hardware (Krasner's hardware was too cumbersome and slow for practical use), was an implementation of a psychoacoustic transform coder based on Motorola 56000 DSP chips. MP3 is directly descended from OCF and PXFM. MP3 represents the outcome of the collaboration of Dr. Karlheinz Brandenburg, working as a postdoc at AT&T-Bell Labs with Mr. James D. Johnston of AT&T-Bell Labs, collaborating with the Fraunhofer Society for Integrated Circuits, Erlangen, with relatively minor contributions from the MP2 branch of psychoacoustic sub-band coders.MPEG-1 Audio Layer 2 encoding began as the Digital Audio Broadcast (DAB) project managed by Egon Meier-Engelen of the Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt (later on called Deutsches Zentrum für Luft- und Raumfahrt, German Aerospace Center) in Germany. The European Community financed this project, commonly known as EU-147, from 1987 to 1994 as a part of the EUREKA research program.The info that available in all post may or may not be true. The Blog owner is not responsible for the false data.The real website link is provided at the end of each post. Please check those website for full information
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