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Information about Wav

Waveform
File extension:.wav
MIME type:audio/wav
audio/wave
audio/x-wav
Type code:WAVE
Uniform Type Identifier:com.microsoft.waveform-​audio
Developed by:Microsoft & IBM
Type of format:audio file
Extended from:RIFF
WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. It is a variant of the RIFF bitstream format method for storing data in “chunks”, and thus also close to the IFF and the AIFF format used on Amiga and Macintosh computers, respectively. It is the main format used on Windows systems for raw audio.

Description

Both WAVs and AIFFs are compatible with Windows and Macintosh operating systems. The format takes into account some differences of the Intel CPU such as little-endian byte order. The RIFF format acts as a “wrapper” for various audio compression codecs.

Though a WAV file can hold compressed audio, the most common WAV format contains uncompressed audio in the pulse-code modulation (PCM) format. PCM audio is the standard audio file format for CDs, containing two channels of 44,100 samples per second, 16 bits per sample. Since PCM uses an uncompressed, lossless storage method, which keeps all the samples of an audio track, professional users or audio experts may use the WAV format for maximum audio quality. WAV audio can also be edited and manipulated with relative ease using software.

Popularity

Uncompressed WAV files are quite large in size, so, as file sharing over the Internet has become popular, the WAV format has declined in popularity. However, it is still a commonly used, relatively “pure”, i.e. lossless, file type, suitable for retaining “first generation” archived files of high quality, or use on a system where high fidelity sound is required and disk space is not restricted.

More frequently, the smaller file sizes of compressed but lossy formats such as MP3, ATRAC, AAC, (Ogg)Vorbis and WMA are used to store and transfer audio. Their small file sizes allow faster Internet transmission, as well as lower consumption of space on memory media. However, lossy formats trade off smaller file size against loss of audio quality, as all such compression algorithms compromise available signal detail. There are also more efficient lossless codecs available, such as FLAC, Shorten, Monkey's Audio, ATRAC Advanced Lossless, Apple Lossless, WMA Lossless, TTA, and WavPack, but none of these is yet a ubiquitous standard for both professional and home audio.

The usage of the WAV format has more to do with its familiarity, its simplicity and simple structure, which is heavily based on the IFF file format. Because of this, it continues to enjoy widespread use with a variety of software applications, often functioning as a 'lowest common denominator' when it comes to exchanging sound files between different programs. Some PlayStation Portable game software uses the AT3 file format which is a WAV file compressed in an ATRAC codec that can be decoded by the unit's libatrac3plus decoder.

In spite of their large size, uncompressed WAV (though that format can be different from the Microsoft WAV) files are sometimes used by a few radio broadcasters, especially those that adopted the tapeless system "D-Cart”, which was developed by the Australian broadcaster ABC. Non compressed formats are used in this application to preserve sound quality, and have become more economical as the cost of data storage has dropped. In the system of “D-Cart”, the sampling rate of WAV files is usually at a 48 kHz 16 bit stereo, which is identical to that of the Digital Audio Tape.

Limitations

The WAV format is limited to files that are less than 4 GB in size, due to its use of a 32 bit unsigned integer to record the file size header (some programs limit the file size to 2-4 GB). Although this is equivalent to about 6.6 hours of CD-quality audio (44.1 kHz, 16-bit stereo), it is sometimes necessary to go over this limit, especially when higher sampling rates or bit resolutions are required. The W64 format was therefore created for use in Sound Forge. Its 64-bit header allows for much longer recording times. This format can be converted using the libsndfile library. The RF64 format specified by the European Broadcasting Union has also been created to solve this problem.

Audio CDs

Audio CDs do not use WAV as their sound format, using instead Red Book audio. The commonality is that both audio CDs and WAV files have the audio data encoded in PCM. WAV is a data file format for computer use that can't be understood by CD players directly. To record WAV files to an Audio CD the file headers must be stripped and the remaining PCM data written directly to the disc as individual tracks with zero padding added to match the CDs sector size.

WAV File Compression Codecs Compared

As mentioned wav files can be encoded with a variety of codecs to reduce the file size (for example the GSM or mp3 codecs).

This is a reference to compare the audio quality and compression bitrates of the different wave compression codecs available for .wav files using the audio compression manager including PCM, GSM, ADPCM, CELP, SBC, TrueSpeech and MPEG Layer-3.

Format Bitrate 1 Min = Sample
11,025 Hz 16 bit PCM176.4 kbs1292 k11k16bitpcm.wav
8,000 Hz 16 bit PCM128 kbs937.5 k8k16bitpcm.wav
11,025 Hz 8 bit PCM88.2 kbs646 k11k8bitpcm.wav
11,025 Hz µ-Law88.2 kbs646 k11kulaw.wav
8,000 Hz 8 bit PCM64 kbs468.8 k8k8bitpcm.wav
8,000 Hz µ-Law64 kbs468.8 k8kulaw.wav
11,025 Hz 4 bit ADPCM44.1 kbs323k11kadpcm.wav
8,000 Hz 4bit ADPCM32 kbs234.4 k8kadpcm.wav
11,025 Hz GSM6.1018 kbs131.8 k11kgsm.wav
8,000 Hz Mp3 16 k16 kbs117 k8kmp316.wav
8,000 Hz GSM6.1013 kbs102.5 k8kgsm.wav
8,000 Hz Lernout & Hauspie SBC 12 k12.0 kbs87.9 k8ksbc12.wav
8,000 Hz DSP Group Truespeech9 kbs65.9 k8ktruespeech.wav
8,000 Hz Mp3 8 k8 kbs60 k8kmp38.wav
8,000 Hz Lernout & Hauspie CELP4.8 kbs35 k8kcelp.wav


These are just the most popular formats. For more samples see the NCH Software ACM reference list (in External Links Below).

The above are wave files – even if they have the mp3 codec they will have the “.wav” extension.

See also

  • Broadcast Wave Format (BWF)
  • RF64, an extended file format for audio (multichannel file format enabling file sizes to exceed 4 gigabytes)

External links

 •  • [ e]
Multimedia compression formats
Video compression formats
ISO/IEC
MJPEG MPEG-1 MPEG-2 MPEG-4 ASP MPEG-4/AVC 		ITU-T
H.261 H.262 H.263 H.264 		Others
AVS Bink Dirac Indeo MJPEG RealVideo Theora VC-1 VP6 VP7 WMV
Audio compression formats
ISO/IEC
MPEG-1 Layer III (MP3) MPEG-1 Layer II MPEG-1 Layer I AAC HE-AAC HE-AAC v2 aacPlus v2 		ITU-T
G.711 G.722 G.722.1 G.722.2 G.723 G.723.1 G.726 G.728 G.729 G.729.1 G.729a 		Others
AC3 Apple Lossless ATRAC FLAC iLBC Monkey's Audio μ-law Musepack Nellymoser OptimFROG RealAudio SHN Speex Vorbis WavPack WMA TAK
Image compression formats
ISO/IEC/ITU-T
JPEG JPEG 2000 lossless JPEG JBIG JBIG2 PNG WBMP 		Others
BMP GIF ILBM PCX PGF TGA TIFF HD Photo
Media container formats
General
3GP ASF AVI DMF DPX FLV Matroska MP4 MXF NUT Ogg Ogg Media QuickTime RealMedia VOB 		Audio only
AIFF AU WAV
See for methods and for codecs
A filename extension is a suffix to the name of a computer file applied to indicate its type. It is commonly used to infer information about what sort of data might be stored in the file.
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Mime or pantomime is a theatrical medium or performance art, involving the acting out of a story by a mime artist through body motions, without use of speech.

History


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A type code is the only mechanism used in pre-Mac OS X versions of the Macintosh operating system to denote a file's format, in a manner similar to file extensions in other operating systems. Codes are four-byte OSTypes.
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A Uniform Type Identifier (UTI) is a string defined by Apple Inc. that uniquely identifies the type of a class of items. Added in Apple's Mac OS X 10.3 operating system, UTIs are used to identify the type of files and folders, clipboard data, bundles, aliases and symlinks,
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Microsoft Corporation

Public (NASDAQ:  MSFT )
Founded Albuquerque, New Mexico, USA (April 4 1975)[1]
Headquarters Redmond, Washington, United States

Key people Bill Gates, Co-founder and Executive Chairman ;
Paul Allen, Co-founder ;
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International Business Machines Corporation

Public (NYSE:  IBM )
Founded 1889, incorporated 1911
Headquarters Armonk, New York, USA

Key people Samuel J.
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An audio format is a medium for storing sound and music. The term is applied to both the physical recording media and the recording formats of the audio content – in computer science it is often limited to the audio file format, but its wider use usually refers to the
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The Resource Interchange File Format (RIFF) is a generic meta-format for storing data in tagged chunks.

It was introduced in 1991 by Microsoft and IBM, and was presented by Microsoft as the default format for Windows 3.1 multimedia files.
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An audio format is a medium for storing sound and music. The term is applied to both the physical recording media and the recording formats of the audio content – in computer science it is often limited to the audio file format, but its wider use usually refers to the
..... Click the link for more information.
Microsoft Corporation

Public (NASDAQ:  MSFT )
Founded Albuquerque, New Mexico, USA (April 4 1975)[1]
Headquarters Redmond, Washington, United States

Key people Bill Gates, Co-founder and Executive Chairman ;
Paul Allen, Co-founder ;
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International Business Machines Corporation

Public (NYSE:  IBM )
Founded 1889, incorporated 1911
Headquarters Armonk, New York, USA

Key people Samuel J.
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An audio file format is a container format for storing audio data on a computer system.

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
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The Resource Interchange File Format (RIFF) is a generic meta-format for storing data in tagged chunks.

It was introduced in 1991 by Microsoft and IBM, and was presented by Microsoft as the default format for Windows 3.1 multimedia files.
..... Click the link for more information.
A bitstream format is the format of the data found in some stream of bits used in a digital communication or storage application. The term typically refers to the format of the output of an encoder or the format of the input to a decoder when using data compression.
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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.
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Audio Interchange File Format (AIFF) is an audio file format standard used for storing sound data for personal computers and other electronic audio devices. The format was co-developed by Apple Computer in 1988 [1] based on Electronic Arts Interchange File Format
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Amiga is a family of personal computers originally developed by Amiga Corporation. Development on the Amiga began in 1982 with Jay Miner (1932-1994) as the principal hardware designer.
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Microsoft Windows

Screenshot of Windows Vista Ultimate, the latest version of Microsoft Windows.
Company/developer: Microsoft Corporation
OS family: MS-DOS/9x-based, Windows CE, Windows NT
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Intel Corporation

Public (NASDAQ:  INTC , SEHK: 4335 )
Founded 1968 1
Headquarters Santa Clara, California
 United States

Key people Paul S.
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codec, see Codec (disambiguation).


A codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. The word codec may be a combination of any of the following: 'Compressor-Dec
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Pulse-code modulation (PCM) is a digital representation of an analog signal where the magnitude of the signal is sampled regularly at uniform intervals, then quantized to a series of symbols in a digital (usually binary) code.
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Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. This can be contrasted to lossy data compression, which does not allow the exact original data to be reconstructed from the
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See Shared resource for the conventional meaning of file sharing
File sharing is the practice of making files available for other users to download over the Internet and smaller networks.
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Internet is a worldwide, publicly accessible series of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government
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MPEG-1 Audio Layer 3

File extension: .mp3
MIME type: audio/mpeg
Type of format: Audio MPEG-1 Audio Layer 3, more commonly referred to as MP3, is an audio encoding format.
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Advanced Audio Coding

File extension: .m4a, .m4b, .m4p, .m4v, .aac, .3gp, .mp4
Type of format: Lossy compression
Container for: Audio

Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for
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Vorbis

File extension: .ogg .oga [1]
MIME type: audio/ogg
Developed by: Xiph.Org Foundation
Type of format: Audio codec
Contained by: Ogg
Standard(s): Specification

Vorbis
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Windows Media Audio

File extension: .wma
MIME type: audio/x-ms-wma
Uniform Type Identifier: com.microsoft.windows-?media-wma
Developed by: Microsoft
Type of format: audio file format Windows Media Audio (WMA
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Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. This can be contrasted to lossy data compression, which does not allow the exact original data to be reconstructed from the
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