IFF

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File Format
Name IFF
Ontology
Extension(s) .iff, many others
LoCFDD fdd000115
PRONOM x-fmt/157
Released 1985
This article is about the generic IFF metaformat. For the IFF image format, see ILBM. For Sun IFF, see Sun TAAC image.

IFF (Interchange File Format) is a general-purpose binary file format introduced by Electronic Arts on the Commodore Amiga computer in 1985. It is sometimes known as IFF 85.

Contents

Format details

An IFF file is composed of elements called "chunks". Each chunk consists of a 4-byte type identifier (represented by four ASCII characters), a 4-byte length, and the chunk's payload data. Some types of chunks contain a sequence of nested chunks. Multi-byte numeric values are big-endian.

IFF defines a number of standard chunks types. Additional types are invented as needed by IFF-based formats.

Of particular significance is chunk type FORM. Most IFF-based files are formatted as a single FORM chunk. A FORM chunk's data contains a four-byte "FORM type" code, indicating the data type, followed by a sequence of nested chunks.

An IFF-based format whose FORM type is xxxx might be referred to as "FORM xxxx". FORM types may also be used as filename extensions.

Identification

Most IFF files begin with the ASCII characters "FORM". The file type is then indicated by the 4-byte ASCII code beginning at offset 8.

There are also aggregate formats that begin with "LIST" or "CAT ".

FORM type cross-reference

Selected FORM types, and related articles, are listed below. See also Category:IFF based file formats.

FORM type Refer to Remarks
8SVX 8-Bit Sampled Voice 8-bit sampled sound voice; listed in the original IFF spec.
ACBM ILBM#ACBM
AIFC AIFC
AIFF AIFF
AMFF Amiga Metafile
ANBM Animated bitmap; listed in the original IFF spec.
ANIM ANIM
D3TV D3TV
DEEP IFF-DEEP
FAXX FAXX
FNTR Raster font; listed in the original IFF spec.
FNTV Vector font; listed in the original IFF spec.
FTXT Formatted text; listed in the original IFF spec.
GSCR General-use musical score; listed in the original IFF spec.
ICON GlowIcons
IFRS Blorb
ILBM ILBM Interleaved raster bitmap image; listed in the original IFF spec.
LWLO, LWOB, LWO2 LightWave Object
MAUD IFF-MAUD Amiga sound format
MAUD MLDF Unknown graphics format
PBM ILBM#PBM
PDEF Deluxe Print page definition; listed in the original IFF spec.
PICS Macintosh picture; listed in the original IFF spec.
PLBM (obsolete); listed in the original IFF spec.
SCDH Sim City 2000 saved city (*.sc2)
SMUS SMUS Simple musical score; listed in the original IFF spec. [1]
TDDD TDDD, Imagine Object File
USCR Uhuru Sound Software musical score; listed in the original IFF spec.
UVOX Uhuru Sound Software Macintosh voice; listed in the original IFF spec.
VAXL VAXL Unknown animation/video format
VDEO VDEO Deluxe Video Construction Set video; listed in the original IFF spec.

Variant formats

Some other formats are largely or heavily influenced by the IFF standard, but are not compatible. These include, for example:

  • Erlang BEAM compiled modules: Uses 4 byte alignment instead of 2 byte, and the root chunk has a different ID (FOR1 instead of FORM)
  • Microsoft's RIFF and RIFX formats are based on IFF (RIFF uses little-endian byte order instead, and the root chunk is called RIFF instead of FORM)
  • Apple's AIFF and AIFC formats are similar to IFF/RIFF as well
  • Maya IFF
  • IFF (The Sims)

Specifications

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