Audio Interchange File Format: Difference between revisions

Revision as of 13:37, 22 October 2020

Revision as of 07:34, 1 December 2020

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With the development of the [[Mac OS X]] operating system, Apple created a new type of AIFF which is, in effect, an alternative [[little-endian]] byte order format.<ref>[https://developer.apple.com/mac/library/documentation/Darwin/Reference/ManPages/man1/say.1.html Mac OS X Reference Library]</ref><ref>[https://developer.apple.com/iphone/library/documentation/musicaudio/Conceptual/CoreAudioOverview/SupportedAudioFormatsMacOSX/SupportedAudioFormatsMacOSX.html Supported Audio File and Data Formats in Mac OS X]</ref>

Because the AIFF architecture has no provision for alternative byte order, Apple used the existing AIFF-C compression architecture, and created a "pseudo-compressed" codec called '''sowt''' ('''twos''' spelled backwards). The only difference between a standard AIFF file and an AIFF-C/sowt file is the byte order; there is no compression involved at all.<ref name='RF04'>{{cite web | author= | title=Technical Q&A QTMRF04: QuickTime Sound | url=https://developer.apple.com/mac/library/qa/qtmrf/qtmrf04.html | publisher=Apple | date=1995-05-01 | accessdate=2009-11-09}}</ref>

Apple uses this new little-endian AIFF type as its standard on Mac OS X. When a file is imported to or exported from [[iTunes]] in "AIFF" format, it is actually AIFF-C/sowt that is being used. When audio from an audio CD is imported by dragging to the Mac OS X Desktop, the resulting file is also an AIFF-C/sowt. In all cases, Apple refers to the files simply as "AIFF", and uses the ".aiff" extension.

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==AIFF Apple Loops==

Apple has also created another recent extension to the AIFF format in the form of Apple Loops<ref>{{cite web|url=https://www.apple.com/logicstudio/soundlibrary/#loops |title=Logic Studio - Plug-ins & Sounds |publisher=Apple |date= |accessdate=2010-04-30}}</ref> used by [[GarageBand]] and [[Logic Pro]], which allows the inclusion of data for pitch and tempo shifting by an application in the more common variety, and [[MIDI]]-sequence data and references to GarageBand playback instruments in another variety.

AppleLoops use either the .aiff (or .aif) or .caf extension regardless of type.

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{| class="wikitable sortable"

|+AIFF-C common compression types<ref name="aiff-spec" /><ref>{{cite web |url=http://shoko.calarts.edu/~tre/AIFFC/comptype.html |title=AIFF-C Compression Types and Names |author=Tom Erbe |year=1999 |accessdate=2010-03-21 |archiveurlarchive-url=https://web.archive.org/web/20060620002145/http://shoko.calarts.edu/~tre/AIFFC/comptype.html |archivedatearchive-date=2006-06-20}}</ref><ref>{{cite web |url=http://hul.harvard.edu/jhove/aiff-hul.html |title=JSTOR/Harvard Object Validation Environment - AIFF-hul Module |date=2005-05-09 |accessdate=2010-03-21 |url-status=dead |archiveurlarchive-url=https://web.archive.org/web/20100629090032/http://hul.harvard.edu/jhove/aiff-hul.html |archivedatearchive-date=2010-06-29 }}</ref>

|-

! Compression type