Broadcast Wave Format

<h2 id="details">Details</h2>
<p>In addition to the common WAVE chunks, the following extension chunks can appear in a Broadcast Wave file:<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a>
</p>
<ul><li>Original Bext chunk (Broadcast Extension - 'bext')</li>
<li><a href="/facts/IXML/0GIcrzel">iXML</a> chunk ('iXML')</li>
<li>Quality chunk ('qlty')</li>
<li>MPEG audio extension chunk ('mext')</li>
<li>Peak Envelope chunk ('levl')</li>
<li>link chunk ('link')</li>
<li>axml chunk ('axml')</li></ul>
<p>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.
</p><p>Unfortunately, this compatibility also preserves the <a href="/facts/WAV/ptUfKleW">filesize limitation</a> 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: <i>cont</i> & <i>link</i> (see list above)
</p><p>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: <i>.wav, .w01, .w02, ..., .wNN</i>.
</p><p>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".
</p><p>As an extension, <a href="/facts/RF64/B7I1L6m0">RF64</a> is a BWF-compatible multichannel file format enabling file sizes to exceed 4 GB that has been specified in 2006.
</p><p>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.
</p><p>In August 2012, the European Broadcasting Union published a specification for embedding <a href="/facts/International_Standard_Recording_Code/24XgqCwd">International Standard Recording Code</a> (ISRC) in the axml chunk of the Broadcast Wave Format.
</p><p>BWF is specified for use in <a href="/facts/Material_Exchange_Format/nw80R93X">MXF</a> by <a href="/facts/SMPTE/lwCdWynu">SMPTE</a> standard 382. BWF is specified for use in <a href="/facts/AES31/aW8BRdYT">AES31</a>.
</p>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/RF64/B7I1L6m0">RF64</a>, A BWF-compatible multichannel file format enabling file sizes to exceed 4 GB</li>
<li><a href="/facts/WAV/ptUfKleW">WAV</a></li>
<li><a href="/facts/Material_Exchange_Format/nw80R93X">MXF</a>, Material eXchange Format</li>
<li><a href="/facts/Advanced_Authoring_Format/J0lXcNj5">Advanced Authoring Format</a></li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://tech.ebu.ch/docs/tech/tech3285s1.pdf">EBU Tech 3285-s1 - Specification of the Broadcast Wave Format (BWF) - Supplement 1, MPEG Audio - first edition (1997)</a></li>
<li><a href="https://tech.ebu.ch/docs/tech/tech3285.pdf">EBU Tech 3285 - Specification of the Broadcast Wave Format (BWF) - Version 1 - second edition (2001)</a></li>
<li><a href="https://tech.ebu.ch/docs/tech/tech3285s2.pdf">EBU Tech 3285-s2 - Specification of the Broadcast Wave Format (BWF) - Supplement 2, Capturing Report - first edition (2001)</a></li>
<li><a href="https://tech.ebu.ch/docs/tech/tech3285s3.pdf">EBU Tech 3285-s3 - Specification of the Broadcast Wave Format (BWF) - Supplement 3, Peak Envelope Chunk - first edition (2001)</a></li>
<li><a href="https://tech.ebu.ch/docs/tech/tech3285s4.pdf">EBU Tech 3285-s4 - Specification of the Broadcast Wave Format (BWF) - Supplement 4, Link Chunk - first edition (2003)</a></li>
<li><a href="https://tech.ebu.ch/docs/tech/tech3285s5.pdf">EBU Tech 3285-s5 - Specification of the Broadcast Wave Format (BWF) - Supplement 5, <axml> Chunk - first edition (2003)</a></li>
<li><a href="https://tech.ebu.ch/docs/tech/tech3352.pdf">EBU Tech 3352 - The Carriage of Identifiers in the Broadcast Wave Format (BWF) (2012 Recommendation)</a></li>
<li><a href="https://tech.ebu.ch/docs/tech/tech3285s6.pdf">EBU Tech 3285-s6 - Specification of the Broadcast Wave Format (BWF) - Supplement 6, Dolby Metadata - <dbmd> Chunk - first edition (2009)</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>IASA Technical Committee, Guidelines on the Production and Preservation of Digital Audio Objects (2009). Bradley, Kevin (ed.). Guidelines on the Production and Preservation of Digital Audio Objects (2nd ed.). Auckland Park, South Africa: International Association of Sound and Audio Visual Archives. ISBN 9789197619226. <a href="9789197619226" target="_blank">9789197619226</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>"EBU BWF User Guide" (PDF). <a href="https://tech.ebu.ch/docs/tech/tech3285.pdf" target="_blank">https://tech.ebu.ch/docs/tech/tech3285.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
</ol>

Broadcast Wave Format open-in-new

Broadcast Wave Format