Audio Interchange File Format: Difference between revisions

Revision as of 15:59, 16 June 2021

Revision as of 00:47, 10 July 2021

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The file extension for the standard AIFF format is '''.aiff''' or '''.aif'''. For the compressed variants it is supposed to be '''.aifc''', but .aiff or .aif are accepted as well by audio applications supporting the format.

==AIFF on Mac OS XmacOS==

{{Original research|section|date=March 2009}}

With the development of the [[Mac OS XmacOS]] 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 | title=Technical Q&A QTMRF04: QuickTime Sound | url=https://developer.apple.com/mac/library/qa/qtmrf/qtmrf04.html | publisher=Apple | date=1995-05-01 | access-date=2009-11-09}}</ref>

Apple uses this new little-endian AIFF type as its standard on Mac OS XmacOS. 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 XmacOS 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.

For the vast majority of users this technical situation is completely unnoticeable and irrelevant. The sound quality of standard AIFF and AIFF-C/sowt are identical, and the data can be converted back and forth without loss. Users of older audio applications, however, may find that an AIFF-C/sowt file will not play, or will prompt the user to convert the format on opening, or will play as static.

All traditional AIFF and AIFF-C files continue to work normally on Mac OS XmacOS (including on the new Intel-based hardware), and many third-party audio applications as well as hardware continue to use the standard AIFF big-endian byte order.

==AIFF Apple Loops==