Broadcast Wave Format (BWF) is an extension of the popular Microsoft WAV audio format and is the recording format of most file-based

non-linear In mathematics and science, a nonlinear system (or a non-linear system) is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathe ...

digital recorders used for

motion picture A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, since ...

, radio and

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. It was first specified by the

European Broadcasting Union The European Broadcasting Union (EBU; , UER) is an alliance of Public broadcasting, public service media organisations in countries within the European Broadcasting Area (EBA) or who are member states of the Council of Europe, members of the ...

in 1997, and updated in 2001 and 2003. It has been accepted as the ITU recommendation ITU-R BS.1352-3, Annex 1. The purpose of this file format is the addition of

metadata Metadata (or metainformation) is "data that provides information about other data", but not the content of the data itself, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive ...

to facilitate the seamless exchange of sound data between different computer platforms and applications. It specifies the format of metadata, allowing audio processing elements to identify themselves, document their activities, and supports timecode to enable synchronization with other recordings. This metadata is stored as extension chunks in a standard digital audio WAV file. BWF is the recommended format for digitizing sound files by the International Association of Sound and Audiovisual Archives. Files conforming to the Broadcast Wave specification have names ending with the

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.WAV.

Details

In addition to the common WAVE chunks, the following extension chunks can appear in a Broadcast Wave file: * Original Bext chunk (Broadcast Extension - 'bext') * iXML chunk ('iXML') * Quality chunk ('qlty') * MPEG audio extension chunk ('mext') * Peak Envelope chunk ('levl') * link chunk ('link') * axml chunk ('axml') Since the only difference between a BWF and a "normal" WAV is the extended information in the file header (Bext-Chunk, Coding-History, etc...), a BWF does not require a special player for playback. Unfortunately, this compatibility also preserves the filesize limitation that WAV files have (4 GB of audio data per data chunk). In order to be able to store audio which would exceed this limit, 2 different chunks exist allowing the audio material to be spread across several files: ''cont'' & ''link'' (see list above) Since there is no official naming convention for these subsequent files, and it is still desirable to see at a glance which ones belong to a continuous piece of audio, a lot of programs apply a numbering scheme to the file suffix: ''.wav, .w01, .w02, ..., .wNN''. Each of those segments is a regular Wave/BWF file, but players that are aware of the continue/link chunk will treat all segments as one single, long piece of audio when opening the first segment ".wav". As an extension, RF64 is a BWF-compatible multichannel file format enabling file sizes to exceed 4 GB that has been specified in 2006. The axml (additional XML) chunk allows users to incorporate data compliant with the XML format with the audio; the chunk may contain data fragments from one or more schema. In August 2012, the European Broadcasting Union published a specification for embedding

International Standard Recording Code The International Standard Recording Code (ISRC) is an international standard code for uniquely identifying sound recordings and music video recordings. The code was developed by the recording industry in conjunction with the International Organiza ...

(ISRC) in the axml chunk of the Broadcast Wave Format. BWF is specified for use in MXF by

SMPTE The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded by Charles Francis Jenkins in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and e ...

standard 382. BWF is specified for use in AES31.

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Details

See also

References

External links