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Encyclopedia > Audio file format

An audio file format is a container format for storing audio data on a computer system. There are numerous file formats for storing audio data. Image File history File links Broom_icon. ... A container format is a computer file format that can contain various types of data, compressed by means of standardized codecs. ... Sound is a disturbance of mechanical energy that propagates through matter as a longitudinal wave, and therefore is a mechanical wave. ... A BlueGene supercomputer cabinet. ...


The general approach towards storing digital audio is to sample the audio voltage (which on playback, would correspond to a certain position of the membrane in a speaker) of the individual chanels with a certain resolution (the number of bits per sample) in regular intervals (forming the sample rate). This data can then be stored uncompressed or compressed to reduce the file size. A sample refers to a value or set of values at a point in time and/or space. ... Resolution in western tonal music theory is the need for a sounded note and/or chord to move from a dissonance or unstable sound to a more final or stable sounding one, a consonance. ... The sampling frequency or sampling rate defines the number of samples per second taken from a continuous signal to make a discrete signal. ...


Types of formats

It is important to distinguish between a file format and a codec. A codec performs the encoding and decoding of the raw audio data while the data itself is stored in a file with a specific audio file format. Though most audio file formats support only one audio codec, a file format may support multiple codecs, as AVI does. A file format is a particular way to encode information for storage in a computer file. ... A Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ... An audio codec is a computer program that compresses/decompresses digital audio data according to a given audio file format or streaming audio format. ... AVI, an acronym for Audio Video Interleave, is a multimedia container format introduced by Microsoft in November 1992, as part of the Video for Windows technology. ...


There are three major groups of audio file formats:

WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. ... Audio Interchange File Format (AIFF) is an audio file format standard used for storing sound data on personal computers. ... The Au file format is a simple audio file format that consists of a header of 6 32-bit words and then the data (high-order byte comes first). ... Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. ... FLAC, an acronym for Free Lossless Audio Codec, is a popular file format for audio data compression. ... Monkey’s Audio is a lossless audio compression codec. ... A filename extension is a suffix to the name of a computer file applied to show its format. ... WavPack is a free, open source lossless audio compression format developed by David Bryant. ... SHN (Shorten) is a file format used to losslessly compress CD-quality audio files (44. ... True Audio (abbreviated TTA) is a free, simple real-time lossless audio codec, based on adaptive prognostic filters which has shown satisfactory results comparing to majority of modern analogs. ... Apple Lossless (also known as Apple Lossless Encoder, ALE, or Apple Lossless Audio Codec, ALAC) is an audio codec developed by Apple Inc. ... Windows Media Audio (WMA) is a proprietary compressed audio file format developed by Microsoft. ... A lossy data compression method is one where compressing data and then decompressing it retrieves data that may well be different from the original, but is close enough to be useful in some way. ... A portable MP3 player MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding, lossy compression format, and algorithm, designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio... Vorbis is an open source, lossy audio codec project headed by the Xiph. ... Windows Media Audio (WMA) is a proprietary compressed audio file format developed by Microsoft. ... Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. ...

Uncompressed audio format

There is one major uncompressed audio format, PCM, which is usually stored as a .wav on Windows or as .aiff on Mac OS. WAV is a flexible file format designed to store more or less any combination of sampling rates or bitrates. This makes it an adequate file format for storing and archiving an original recording. A lossless compressed format would require more processing for the same time recorded, but would be more efficient in terms of space used. WAV, like any other uncompressed format, encodes all sounds, whether they are complex sounds or absolute silence, with the same number of bits per unit of time. PCM is an initialism which can have different meanings: Phase Change Material Pulse-code modulation, a way to digitally encode signals representing sound and their video counterparts Potential Cancer Marker Communist Party of Mexico Plug Compatible Manufacturer Power-train control module, a computer in a car which controls the car... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... This article or section does not adequately cite its references or sources. ...


Let's take an example. A file contains a minute of a symphonic orchestra playing beautifully followed by a minute of silence. If the sound were stored in WAV, the same amount of data would be used for each half. If data were encoded with TTA, the first minute would be a bit smaller than in the WAV file, and the silent half would take almost no disc space at all. But then, recording in the TTA format would require a lot more processing than the WAV.


The WAV format is based on the RIFF file format, which is similar to the IFF format. The Resource Interchange File Format (RIFF) is a generic meta-format for storing data in tagged chunks. ... Interchange File Format (IFF), is a generic file format originally introduced by the Electronic Arts company in 1985 (in cooperation with Commodore-Amiga) in order to ease transfer of data between software products produced by different companies. ...


BWF (Broadcast Wave Format) is a standard audio format created by the European Broadcasting Union as a successor to WAV. BWF allows metadata to be stored in the file. See: European Broadcasting Union: Specification of the Broadcast Wave Format - A format for audio data files in broadcasting. EBU Technical document 3285, July 1997. This format is the primary recording format used in many professional Audio Workstations used in the Television and Film industry. Stand-alone file based multi-track recorders from Sound Devices, Zaxcom, HHB USA, Fostex, and Aaton all use BWF as their preferred file format for recording multi-track audio files with SMPTE Time Code reference. This standardized Time Stamp in the Broadcast Wave File allows for easy synchronization with a separate picture element. BWF is an abbreviation of Broadcast Wave file Format . ... <marquee bgcolor=white><text color=lime> sup --> The European Broadcasting Union (EBU), known in French as LUnion Européenne de Radio-Télévision (UER), and unrelated to the European Union, was formed on 12 February 1950 by 23 broadcasting organisations from Europe and the Mediterranean at a conference... Metadata (Greek meta after and Latin data information) are data that describe other data. ... 1997 (MCMXCVII) was a common year starting on Wednesday of the Gregorian calendar. ... Fostex is a Japanese manufacturer of loudspeakers and professional audio equipment. ...


Lossless audio formats

Lossless audio formats (such as TTA and FLAC) provide a compression ratio of about 2:1. TTA may refer to Telecommunications Technology Association in Korea Tennessee Telecommunications Association, a telecommunications industry trade organization Tennessee Trails Association Terran Trade Authority, a science-fiction universe Texas Telephone Association, a trade association for telephone companies in Texas The Tough Alliance, a synthpop duo from Sweden Time triggered architecture, software... FLAC, an acronym for Free Lossless Audio Codec, is a popular file format for audio data compression. ...


  Results from FactBites:
 
AU - Audio File Format (582 words)
An audio file is composed of three parts: a 24-byte header, a variable-length annotation block, and a contiguous segment of audio data.
Audio header and data fields are stored in network (big-endian) byte order, regardless of the native byte-order of the machine architecture on which an application may be running.
Audio data is encoded in the format identified by the file header.
Introduction to HTML - Audio File Formats (473 words)
The AIFC format is an extension of the AIFF format with file compression.
The quality of the audio playback is determined not only by the sophistication of the decoder used but also by the sampling rate at with the sound was encoded, and the degree of file compression.
File size depends on the length of the recorded performance and on the sampling rate used to record and encode the audio information for playback.
  More results at FactBites »

 
 

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