{"history":[],"article":{"id":"f00c5490-c819-4769-a32e-617618231273","title":"WAV","slug":"wav","content":":::summary\n**Name:** Waveform Audio File Format (WAVE/WAV) \n**Icon:** AudacityWAV.png \n**Extension:** .wav .wave \n**Mime:** audio/vnd.wave, audio/wav, audio/wave, audio/x-wav \n**Type Code:** WAVE \n**Uniform Type:** com.microsoft.waveform-audio \n**Owner:** [IBM](https://bliptext.com/articles/ibm) and [Microsoft](https://bliptext.com/articles/microsoft) \n**Released:** August 1991 \n**Latest Release Version:** Multiple Channel Audio Data and WAVE Files \n**Latest Release Date:** March 7, 2007 (update) \n**Genre:** [Audio file format](https://bliptext.com/articles/audio-file-format), [container format](https://bliptext.com/articles/container-format-digital) \n**Extended From:** [RIFF](https://bliptext.com/articles/resource-interchange-file-format) \n**Extended To:** [BWF](https://bliptext.com/articles/broadcast-wave-format), [RF64](https://bliptext.com/articles/rf64) \n:::\n\n# \n**Waveform Audio File Format** (****WAV**E**, or **WAV** due to its [filename extension](https://bliptext.com/articles/filename-extension); pronounced or ) is an [audio file format](https://bliptext.com/articles/audio-file-format) standard for storing an audio [bitstream](https://bliptext.com/articles/bitstream) on [personal computers](https://bliptext.com/articles/personal-computer).\nThe format was developed and published for the first time in 1991 by [IBM](https://bliptext.com/articles/ibm) and [Microsoft](https://bliptext.com/articles/microsoft).\nIt is the main format used on [Microsoft Windows](https://bliptext.com/articles/microsoft-windows) systems for [uncompressed audio](https://bliptext.com/articles/uncompressed-audio).\nThe usual bitstream encoding is the [linear pulse-code modulation](https://bliptext.com/articles/linear-pulse-code-modulation) (LPCM) format.\nWAV is an application of the [Resource Interchange File Format](https://bliptext.com/articles/resource-interchange-file-format) (RIFF) [bitstream format](https://bliptext.com/articles/bitstream-format) method for storing data in chunks, and thus is similar to the [8SVX](https://bliptext.com/articles/8svx) and the [Audio Interchange File Format](https://bliptext.com/articles/audio-interchange-file-format) (AIFF) format used on [Amiga](https://bliptext.com/articles/amiga) and [Macintosh](https://bliptext.com/articles/apple-macintosh) computers, respectively.\n\n# Description\nThe WAV file is an instance of a [Resource Interchange File Format](https://bliptext.com/articles/resource-interchange-file-format) (RIFF) defined by [IBM](https://bliptext.com/articles/ibm) and [Microsoft](https://bliptext.com/articles/microsoft).\nThe RIFF format acts as a wrapper for various [audio coding formats](https://bliptext.com/articles/audio-coding-format).\nThough a WAV file can contain [compressed](https://bliptext.com/articles/audio-data-compression) audio, the most common WAV audio format is un[compressed](https://bliptext.com/articles/audio-data-compression) audio in the [linear pulse-code modulation](https://bliptext.com/articles/linear-pulse-code-modulation) (LPCM) format.\nLPCM is also the standard audio coding format for [audio CDs](https://bliptext.com/articles/audio-cd), which store two-channel LPCM audio [sampled](https://bliptext.com/articles/sampling-signal-processing) at [44.1 kHz](https://bliptext.com/articles/44-1-khz) with 16 [bits per sample](https://bliptext.com/articles/audio-bit-depth).\nSince LPCM is uncompressed and retains all of the samples of an audio track, professional users or audio experts may use the WAV format with LPCM audio for maximum audio quality.\nWAV files can also be edited and manipulated with relative ease using software.\nOn Microsoft Windows, the WAV format supports compressed audio using the [Audio Compression Manager](https://bliptext.com/articles/audio-compression-manager) (ACM).\nAny ACM [codec](https://bliptext.com/articles/codec) can be used to compress a WAV file.\nThe [user interface](https://bliptext.com/articles/user-interface) (UI) for ACM may be accessed through various programs that use it, including [Sound Recorder](https://bliptext.com/articles/sound-recorder-windows) in some versions of Windows.\nBeginning with [Windows 2000](https://bliptext.com/articles/windows-2000), a header was defined which specifies [multiple audio channel data](https://bliptext.com/articles/surround-sound) along with speaker positions, eliminates ambiguity regarding sample types and container sizes in the standard WAV format and supports defining custom extensions to the format.\n\n# File specifications\n\n## RIFF\nA RIFF file is a tagged file format.\nIt has a specific container format (a chunk) with a header that includes a four-character tag ([FourCC](https://bliptext.com/articles/fourcc)) and the size (number of bytes) of the chunk.\nThe tag specifies how the data within the chunk should be interpreted, and there are several standard FourCC tags.\nTags consisting of all capital letters are reserved tags.\nThe outermost chunk of a RIFF file has a tag; the first four bytes of chunk data are an additional FourCC tag that specify the form type and are followed by a sequence of subchunks.\nIn the case of a WAV file, the additional tag is.\nThe remainder of the RIFF data is a sequence of chunks describing the audio information.\nThe advantage of a tagged file format is that the format can be extended later while maintaining [backward compatibility](https://bliptext.com/articles/backward-compatibility).\nThe rule for a RIFF (or WAV) reader is that it should ignore any tagged chunk that it does not recognize.\nThe reader will not be able to use the new information, but the reader should not be confused.\nThe specification for RIFF files includes the definition of an chunk.\nThe chunk may include information such as the title of the work, the author, the creation date, and copyright information.\nAlthough the chunk was defined for RIFF in version 1.0, the chunk was not referenced in the formal specification of a WAV file.\nMany readers had trouble processing this.\nConsequently, the safest thing to do from an interchange standpoint was to omit the chunk and other extensions and send a lowest-common-denominator file.\nThere are other [INFO chunk placement problems](https://bliptext.com/articles/resource-interchange-file-format).\nRIFF files were expected to be used in international environments, so there is chunk to specify the country code, language, dialect, and [code page](https://bliptext.com/articles/code-page) for the strings in a RIFF file.\nFor example, specifying an appropriate chunk should allow the strings in an chunk (and other chunks throughout the RIFF file) to be interpreted as Cyrillic or Japanese characters.\nRIFF also defines a chunk whose contents are uninteresting.\nThe chunk allows a chunk to be deleted by just changing its FourCC.\nThe chunk could also be used to reserve some space for future edits so the file could be modified without being resized.\nA later definition of RIFF introduced a similar chunk.\n\n## RIFF WAVE\nThe top-level definition of a WAV file is:\n → RIFF('WAVE' // Format of the file [] // Fact chunk [] // Cue points [] // Playlist [] // Associated data list ) // Wave data\nThe top-level RIFF form uses a tag.\nIt is followed by a mandatory chunk that describes the format of the sample data that follows.\nThis chunk includes information such as the sample encoding, number of bits per channel, the number of channels, and the sample rate.\nThe WAV specification includes some optional features.\nThe optional chunk reports the number of samples for some compressed coding schemes.\nThe chunk identifies some significant sample numbers in the wave file.\nThe chunk allows the samples to be played out of order or repeated rather than just from beginning to end.\nThe associated data list allows labels and notes to be attached to cue points; text annotation may be given for a group of samples (e.g., caption information).\nFinally, the mandatory chunk contains the actual samples in the format previously specified.\nNote that the WAV file definition does not show where an chunk should be placed.\nIt is also silent about the placement of a chunk (which specifies the character set used).\nThe RIFF specification attempts to be a formal specification, but its formalism lacks the precision seen in other tagged formats.\nFor example, the RIFF specification does not clearly distinguish between a set of subchunks and an ordered sequence of subchunks.\nThe RIFF form chunk suggests it should be a sequence container.\nSequencing information is specified in the RIFF form of a WAV file consistent with the formalism: \"However, must always occur before , and both of these chunks are mandatory in a WAVE file.\"\nThe specification suggests a chunk is also a sequence: \"A LIST chunk contains a list, or ordered sequence, of subchunks.\"\nHowever, the specification does not give a formal specification of the chunk; an example chunk ignores the chunk sequence implied in the description.\nThe chunk definition for does use the chunk as a sequence container with good formal semantics.\nThe WAV specification supports, and most WAV files use, a single contiguous array of audio samples.\nThe specification also supports discrete blocks of samples and silence that are played in order.\nThe specification for the sample data contains apparent errors:\nThe contains the waveform data.\nIt is defined as follows:\n → { (undefined) and (defined but not referenced) should be identical.\nEven with this resolved, the productions then allow a to contain a [recursive](https://bliptext.com/articles/recursion-computer-science) (which implies data interpretation problems).\nTo avoid the recursion, the specification can be interpreted as:\n → { extension.\nThis is a reference to compare the [monophonic](https://bliptext.com/articles/monaural) (not [stereophonic](https://bliptext.com/articles/stereophonic)) audio quality and compression bitrates of audio coding formats available for WAV files including LPCM, [ADPCM](https://bliptext.com/articles/adpcm), Microsoft [GSM 06.10](https://bliptext.com/articles/gsm-06-10), [CELP](https://bliptext.com/articles/celp), [SBC](https://bliptext.com/articles/smart-bitrate-control), [Truespeech](https://bliptext.com/articles/truespeech) and [MPEG](https://bliptext.com/articles/mpeg) Layer-3.\nThese are the default ACM codecs that come with Windows.","current_revision":null,"created_by":"kACnuQmH5k9Nr5VNVEpVeg7XpvUmMctD","created_at":"2025-01-25T16:35:11.472Z","updated_at":"2025-01-25T16:35:11.472Z","search_vector":"'wav':1","search_content":" \n**Name:** Waveform Audio File Format (WAVE/WAV) \n**Icon:** AudacityWAV.png \n**Extension:** .wav .wave \n**Mime:** audio/vnd.wave, audio/wav, audio/wave, audio/x-wav \n**Type Code:** WAVE \n**Uniform Type:** com.microsoft.waveform-audio \n**Owner:** [IBM](https://bliptext.com/articles/ibm) and [Microsoft](https://bliptext.com/articles/microsoft) \n**Released:** August 1991 \n**Latest Release Version:** Multiple Channel Audio Data and WAVE Files \n**Latest Release Date:** March 7, 2007 (update) \n**Genre:** [Audio file format](https://bliptext.com/articles/audio-file-format), [container format](https://bliptext.com/articles/container-format-digital) \n**Extended From:** [RIFF](https://bliptext.com/articles/resource-interchange-file-format) \n**Extended To:** [BWF](https://bliptext.com/articles/broadcast-wave-format), [RF64](https://bliptext.com/articles/rf64) \n \n\n# \n**Waveform Audio File Format** (****WAV**E**, or **WAV** due to its [filename extension](https://bliptext.com/articles/filename-extension); pronounced or ) is an [audio file format](https://bliptext.com/articles/audio-file-format) standard for storing an audio [bitstream](https://bliptext.com/articles/bitstream) on [personal computers](https://bliptext.com/articles/personal-computer).\nThe format was developed and published for the first time in 1991 by [IBM](https://bliptext.com/articles/ibm) and [Microsoft](https://bliptext.com/articles/microsoft).\nIt is the main format used on [Microsoft Windows](https://bliptext.com/articles/microsoft-windows) systems for [uncompressed audio](https://bliptext.com/articles/uncompressed-audio).\nThe usual bitstream encoding is the [linear pulse-code modulation](https://bliptext.com/articles/linear-pulse-code-modulation) (LPCM) format.\nWAV is an application of the [Resource Interchange File Format](https://bliptext.com/articles/resource-interchange-file-format) (RIFF) [bitstream format](https://bliptext.com/articles/bitstream-format) method for storing data in chunks, and thus is similar to the [8SVX](https://bliptext.com/articles/8svx) and the [Audio Interchange File Format](https://bliptext.com/articles/audio-interchange-file-format) (AIFF) format used on [Amiga](https://bliptext.com/articles/amiga) and [Macintosh](https://bliptext.com/articles/apple-macintosh) computers, respectively.\n\n# Description\nThe WAV file is an instance of a [Resource Interchange File Format](https://bliptext.com/articles/resource-interchange-file-format) (RIFF) defined by [IBM](https://bliptext.com/articles/ibm) and [Microsoft](https://bliptext.com/articles/microsoft).\nThe RIFF format acts as a wrapper for various [audio coding formats](https://bliptext.com/articles/audio-coding-format).\nThough a WAV file can contain [compressed](https://bliptext.com/articles/audio-data-compression) audio, the most common WAV audio format is un[compressed](https://bliptext.com/articles/audio-data-compression) audio in the [linear pulse-code modulation](https://bliptext.com/articles/linear-pulse-code-modulation) (LPCM) format.\nLPCM is also the standard audio coding format for [audio CDs](https://bliptext.com/articles/audio-cd), which store two-channel LPCM audio [sampled](https://bliptext.com/articles/sampling-signal-processing) at [44.1 kHz](https://bliptext.com/articles/44-1-khz) with 16 [bits per sample](https://bliptext.com/articles/audio-bit-depth).\nSince LPCM is uncompressed and retains all of the samples of an audio track, professional users or audio experts may use the WAV format with LPCM audio for maximum audio quality.\nWAV files can also be edited and manipulated with relative ease using software.\nOn Microsoft Windows, the WAV format supports compressed audio using the [Audio Compression Manager](https://bliptext.com/articles/audio-compression-manager) (ACM).\nAny ACM [codec](https://bliptext.com/articles/codec) can be used to compress a WAV file.\nThe [user interface](https://bliptext.com/articles/user-interface) (UI) for ACM may be accessed through various programs that use it, including [Sound Recorder](https://bliptext.com/articles/sound-recorder-windows) in some versions of Windows.\nBeginning with [Windows 2000](https://bliptext.com/articles/windows-2000), a header was defined which specifies [multiple audio channel data](https://bliptext.com/articles/surround-sound) along with speaker positions, eliminates ambiguity regarding sample types and container sizes in the standard WAV format and supports defining custom extensions to the format.\n\n# File specifications\n\n## RIFF\nA RIFF file is a tagged file format.\nIt has a specific container format (a chunk) with a header that includes a four-character tag ([FourCC](https://bliptext.com/articles/fourcc)) and the size (number of bytes) of the chunk.\nThe tag specifies how the data within the chunk should be interpreted, and there are several standard FourCC tags.\nTags consisting of all capital letters are reserved tags.\nThe outermost chunk of a RIFF file has a tag; the first four bytes of chunk data are an additional FourCC tag that specify the form type and are followed by a sequence of subchunks.\nIn the case of a WAV file, the additional tag is.\nThe remainder of the RIFF data is a sequence of chunks describing the audio information.\nThe advantage of a tagged file format is that the format can be extended later while maintaining [backward compatibility](https://bliptext.com/articles/backward-compatibility).\nThe rule for a RIFF (or WAV) reader is that it should ignore any tagged chunk that it does not recognize.\nThe reader will not be able to use the new information, but the reader should not be confused.\nThe specification for RIFF files includes the definition of an chunk.\nThe chunk may include information such as the title of the work, the author, the creation date, and copyright information.\nAlthough the chunk was defined for RIFF in version 1.0, the chunk was not referenced in the formal specification of a WAV file.\nMany readers had trouble processing this.\nConsequently, the safest thing to do from an interchange standpoint was to omit the chunk and other extensions and send a lowest-common-denominator file.\nThere are other [INFO chunk placement problems](https://bliptext.com/articles/resource-interchange-file-format).\nRIFF files were expected to be used in international environments, so there is chunk to specify the country code, language, dialect, and [code page](https://bliptext.com/articles/code-page) for the strings in a RIFF file.\nFor example, specifying an appropriate chunk should allow the strings in an chunk (and other chunks throughout the RIFF file) to be interpreted as Cyrillic or Japanese characters.\nRIFF also defines a chunk whose contents are uninteresting.\nThe chunk allows a chunk to be deleted by just changing its FourCC.\nThe chunk could also be used to reserve some space for future edits so the file could be modified without being resized.\nA later definition of RIFF introduced a similar chunk.\n\n## RIFF WAVE\nThe top-level definition of a WAV file is:\n → RIFF('WAVE' // Format of the file [ ] // Fact chunk [ ] // Cue points [ ] // Playlist [ ] // Associated data list ) // Wave data\nThe top-level RIFF form uses a tag.\nIt is followed by a mandatory chunk that describes the format of the sample data that follows.\nThis chunk includes information such as the sample encoding, number of bits per channel, the number of channels, and the sample rate.\nThe WAV specification includes some optional features.\nThe optional chunk reports the number of samples for some compressed coding schemes.\nThe chunk identifies some significant sample numbers in the wave file.\nThe chunk allows the samples to be played out of order or repeated rather than just from beginning to end.\nThe associated data list allows labels and notes to be attached to cue points; text annotation may be given for a group of samples (e.g., caption information).\nFinally, the mandatory chunk contains the actual samples in the format previously specified.\nNote that the WAV file definition does not show where an chunk should be placed.\nIt is also silent about the placement of a chunk (which specifies the character set used).\nThe RIFF specification attempts to be a formal specification, but its formalism lacks the precision seen in other tagged formats.\nFor example, the RIFF specification does not clearly distinguish between a set of subchunks and an ordered sequence of subchunks.\nThe RIFF form chunk suggests it should be a sequence container.\nSequencing information is specified in the RIFF form of a WAV file consistent with the formalism: \"However, must always occur before , and both of these chunks are mandatory in a WAVE file.\"\nThe specification suggests a chunk is also a sequence: \"A LIST chunk contains a list, or ordered sequence, of subchunks.\"\nHowever, the specification does not give a formal specification of the chunk; an example chunk ignores the chunk sequence implied in the description.\nThe chunk definition for does use the chunk as a sequence container with good formal semantics.\nThe WAV specification supports, and most WAV files use, a single contiguous array of audio samples.\nThe specification also supports discrete blocks of samples and silence that are played in order.\nThe specification for the sample data contains apparent errors:\nThe contains the waveform data.\nIt is defined as follows:\n → { (undefined) and (defined but not referenced) should be identical.\nEven with this resolved, the productions then allow a to contain a [recursive](https://bliptext.com/articles/recursion-computer-science) (which implies data interpretation problems).\nTo avoid the recursion, the specification can be interpreted as:\n → { extension.\nThis is a reference to compare the [monophonic](https://bliptext.com/articles/monaural) (not [stereophonic](https://bliptext.com/articles/stereophonic)) audio quality and compression bitrates of audio coding formats available for WAV files including LPCM, [ADPCM](https://bliptext.com/articles/adpcm), Microsoft [GSM 06.10](https://bliptext.com/articles/gsm-06-10), [CELP](https://bliptext.com/articles/celp), [SBC](https://bliptext.com/articles/smart-bitrate-control), [Truespeech](https://bliptext.com/articles/truespeech) and [MPEG](https://bliptext.com/articles/mpeg) Layer-3.\nThese are the default ACM codecs that come with Windows.","revisionCount":0},"hasMore":false,"nextCursor":null}

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