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AIFF (Audio Interchange File Format)

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name Audio Interchange File Format (AIFF)
Description File format for sound that wraps various sound bitstreams, ranging from uncompressed waveform to MIDI. Files with LPCM waveform data are the focus of this discussion. Compressed waveforms are wrapped by AIFF-C (or an earlier version sometimes referred to as AIFC), not documented at this web site.
Production phase Used primarily as a initial- or middle-state format, including use as a master file for audio captured live digitally or reformatted from analog sources.
Relationship to other formats
    Subtype of IFF, Electronic Arts Interchange File Format 1985
    Has subtype AIFF_LPCM, AIFF with LPCM Audio
    Has subtype AIFF-C in which the "C" signifies its extension to handle compressed audio data (August 1991, not documented at this Web site at this time)
    Has subtype AIFF files may contain other sound encodings not documented here
    May contain LPCM, Linear Pulse Code Modulated Audio (LPCM). encoded audio
    May contain MIDI_SD, MIDI sequence data
    May contain Other sound encodings, not documented here

Local use Explanation of format description terms

LC experience or existing holdings None
LC preference General preference for recorded sound is WAVE_LPCM.

Sustainability factors Explanation of format description terms

Disclosure

Fully documented. Developed by Apple Computer, Inc.

    Documentation

AIFF and AIFF-C documentation produced by Apple and carrying no copyright notice is available from third parties. The principal document is titled Audio Interchange File Format (AIFF): A Standard for Samples Sound Files, Version 1.3 (Apple Computer, Inc) and it also forms Annex C to the CD-I IFF specification published by the American Interactive Media group. The compiler of this document was unable to locate the specifications at the Apple web site.

Adoption

Widely adopted among Apple users engaged in professional audio work; some adoption beyond, although most Windows users select WAVE, which is functionally equivalent. AIFF_LPCM is used as the master format by the Harvard University Library Digital Initiative audio reformatting activity.

    Licensing and patents

None known to the compilers of this document.

Transparency

Wrapper is transparent. The transparency of the audio bitstreams is a function of the encoding used; for example, see LPCM.

Self-documentation

AIFF includes various chunks, each with a header that provides technical information; text chunks as defined from the supertype IFF format include name, author, copyright, and annotation.

External dependencies None
Technical protection considerations

None known to the compilers of this document.


Quality and functionality factors Explanation of format description terms

Sound
Normal rendering Good support.
Fidelity (high audio resolution) Excellent to good, depending upon encoding parameters selected.
Multiple channels Mono, stereo, 3-channel, quad, and four and six channel surround sound are supported for waveform data, depending upon encoding; MIDI data may carry multi-channel information. [?]
Support for user-defined sounds, samples, and patches Not researched for this document
Functionality beyond normal rendering Not applicable; added functionality may be associated with non-waveform data.

File type signifiers Explanation of format description terms

Tag Value Note
Filename extension aif
aiff
ief
aif is most widely used as a file extension. Wikipedia reports use of aiff. Webopedia reports that ief is used as an extension.
Internet Media Type audio/aiff
audio/x-aiff
sound/aiff
audio/rmf
audio/x-rmf
audio/x-pn-aiff
audio/x-gsm
audio/x-midi
audio/vnd.qcelp
From The File Extension Source. Note that encoding, e.g., gsm, midi and qcelp, is often a part of the MIME string. Internet Media Type for AIFF not found at http://www.iana.org/assignments/media-types/.
Magic numbers Hex: 46 4F 52 4D 00
ASCII: FORM
From The File Extension Source.
Mac OS file type AIFF
 

Notes Explanation of format description terms

General  
History  

Format specifications Explanation of format description terms


Useful references

URLs


Last Updated: 05/28/2014