Interchange File Format (IFF), is a generic file format originally introduced by the Electronic Arts company in 1985 (in cooperation with Commodore-Amiga) in order to ease transfer of data between software products produced by different companies. A file format is a particular way to encode information for storage in a computer file. ... EA redirects here. ... The original Amiga 1000 (1985) with various peripherals The Amiga is a family of personal computers originally developed by Amiga Corporation. ...

IFF files do not have any common extension. Most files with .iff extension are in fact ILBM files, wrongly named so because they are most common IFF files and most assume that they are the only type of IFF files (on many systems that produce IFF files, file extensions are not important). A filename extension or filename suffix is an extra set of (usually) alphanumeric characters that is appended to the end of a filename to allow computer users (as well as various pieces of software on the computer system) to quickly determine the type of data stored in the file. ... ILBM is a subtype of the Interchange File Format used for storing picture data. ...

Structure

An IFF file is built up from chunks. Each chunk begins with what the spec calls a "Type ID" (what the Macintosh called an OSType and Windows developers might call a FourCC). This is followed by a 32-bit unsigned integer (all integers in IFF files' structure are big-endian) specifying the size of the following data (the chunk content) in bytes. Because the spec includes explicit lengths for each chunk, it is possible for a parser to skip over chunks which it either can't or doesn't care to process. The first Macintosh computer, introduced in 1984, upgraded to a 512K Fat Mac. The Macintosh or Mac, is a line of personal computers designed, developed, manufactured, and marketed by Apple Computer. ... OSType (also known as FourCC or ResType) is the name of a four-byte type commonly used as an identifier in Mac OS. The four bytes could in principle have any binary value, though they are usually ASCII or characters from the Mac Roman character set. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... A FOURCC (literally, four character code) is a sequence of four bytes used to uniquely identify data formats. ... The integers are commonly denoted by the above symbol. ... When integers or any other data are represented with multiple bytes, there is no unique way of ordering of those bytes in memory or in a transmission over some medium, and so the order is subject to arbitrary convention. ...

There are predefined group chunks, with type IDs ‘FORM’, ‘LIST’ and ‘CAT ’. A FORM chunk is like a record structure, containing a type ID (indicating the record type) followed by nested chunks specifying the record fields. A LIST is a factoring structure containing a series of ‘PROP’ (property) chunks plus nested group chunks to which those properties apply. A CAT  is just a collection of nested chunks with no special semantics. Group chunks can contain other group chunks, depending on the needs of the application. Group chunks, like their simpler counterparts, contain a length element. Skipping over a group can thus be done with a simple Unix-style relative seek operation.

Chunks must begin on even file offsets, as befits the origins of IFF on the Motorola 68000 processor, which couldn't address quantities larger than a byte on odd addresses. Thus a chunk following an odd-length chunk will be preceded by a pad byte. The Motorola 68000 is a CISC microprocessor, the first member of a successful family of microprocessors from Motorola, which were all mostly software compatible. ...

The top-level structure of an IFF file consists of exactly one of the group chunks: FORM, LIST or CAT .

Each type of chunk typically has different internal structure, that could be numerical data, text, or raw data. It is also possible to include other IFF files as if they are chunks (note that they have the same structure: four letters followed with length) and some formats use this. There are standard chunks that could be present in any IFF file, such as ‘AUTH’ (containing text with information about author of the file), ‘ANNO’ (containing text with annotation, usually name of the program that created the file), ‘NAME’ (containing text with name of the work in the file), ‘VERS’ (containing file version), ‘(c) ’ (containing text with copyright information). There are also chunks that are common among a number of formats, such as ‘CMAP’ which holds color palette in ILBM, ANIM and DR2D files (pictures, animations and vector pictures). There are chunks that have common name but hold different data such as ‘BODY’ which could store image in an ILBM file and sound in an 8SVX file. And finally, there are chunks unique to their file type. Some programs that create IFF files add to them chunks with their internal data; these same files can later be read by other programs without any disruption (because their parsers could skip uninteresting chunks) which is a great advantage of IFF and similar formats. ILBM is a subtype of the Interchange File Format used for storing picture data. ... ILBM is a subtype of the Interchange File Format used for storing picture data. ... 8SVX is a subformat of the Interchange File Format. ...

As a nestable, descriptive file format, there are architectural similaries to XML. XML, however, is primarily a text format, whereas all IFF contains at least some binary data (the length fields). It is possible to mechanically convert IFF to an XML equivalent; however, XML has additional features such as descriptive data and metadata (attributes, entities, DTD's and schemas) and navigational features (xpath) which cannot be trivially mapped back to IFF.

List of common IFF-based file formats

• 8SVX (Audio format)
• ACBM (Amiga Contiguous BitMap - Image format for very fast loading/saving)
• AIFF (Audio format)
• ANBM ((obsolete) animation format, interally a set of ILBMs to be displayed one-after-another)
• ANIM (Animation format)
• BIFF8 (formerly used by Microsoft Excel)
• Alias/Wavefront Maya file format (both image and scene description)
• Word document (pre Word 97 format)
• DjVu (Image format for high resolution compound documents)
• DR2D (two-dimensional drawings)
• EMOD (QuadraComposer module format)
• FNTR (Raster font)
• FNTV (Vector font)
• FPBM (LightWave Flexible Precision Buffer Map picture)
• FTXT (Text format)
• GSCR (apocryphal (?) General music Score)
• IFRS (known as Blorb)
• IFZS (known as Quetzal)
• ILBM (Raster image format)
• LWOB (LightWave 3d object format)
• LWO2 (LightWave 3d object format)
• PDEF (Deluxe Print page definition)
• PICS (Macintosh QuickDraw picture encapsulated in IFF format)
• PLBM ((obsolete) picture format)
• SHRI
• SMUS (Simple Music format, similar to MIDI format)
• TDDD (Imagine 3d object format)
• USCR (Uhuru Sound music score)
• UVOX (Uhuru Sound voice)
• VDEO (Deluxe Video Construction Set video)
• YAFA (Animation Format)

8SVX is a subformat of the Interchange File Format. ... Audio Interchange File Format (AIFF) is an audio file format standard used for storing sound data on personal computers. ... Anim - fountains, a city in the mountains of Judah (Josh. ... This article or section does not adequately cite its references or sources. ... This article or section does not cite any references or sources. ... Microsoft Office Word is Microsofts flagship word processing software. ... DjVu (pronounced déjà vu) is a computer file format designed primarily to store scanned images, especially those containing text and line drawings. ... An assortment of bitmap fonts from the first version of the Macintosh operating system A bitmap font is one that stores each glyph as an array of pixels (that is, a bitmap). ... An outline font (or vector font) is one defined as vector graphics, i. ... LightWave (or, more properly, LightWave 3D) is a computer graphics program for 3D modeling, animating and rendering. ... Blorb is a package format for interactive fiction games. ... Quetzal is a standardised file format for the saved state of Z-machine games, invented by Martin Frost. ... ILBM is a subtype of the Interchange File Format used for storing picture data. ... Suppose the smiley face in the top left corner is an RGB bitmap image. ... LightWave (or, more properly, LightWave 3D) is a computer graphics program for 3D modeling, animating and rendering. ... LightWave (or, more properly, LightWave 3D) is a computer graphics program for 3D modeling, animating and rendering. ... SMUS can stand for St. ... Imagine was the name of a cutting edge 3d modeling and raytracing program, originally for the Amiga computer and later also for Microsoft Windows. ...

Clones and variants of the IFF format

• RIFF is a variant of IFF format devised by Microsoft and IBM; RIFF files differ from IFF files in that they have letters RIFF at the beginning and use little-endian integers. WAV files, for example, are RIFFs. A big-endian version, RIFX, has also been defined but found no significant use.
• AVI files are also RIFF-based
• The TIFF file format was designed by Aldus to include high-depth bitmaps with PostScript. It has a chunked structure similar to IFF, however the image format itself has no relationship to the ILBM format.
• The Standard MIDI File format takes the key concepts of IFF without actually using the IFF standard.
• The PNG file format takes the concept of chunks from IFF, but does not copy the exact structure.
• QuickTime (.mov) files (and hence the derived MPEG-4 files) took the same concept of chunks from IFF, but calls them 'atoms' and uses a different layout. They also have extensions for chunks over 4GB in size.
• 3dstudio (.3ds) 3d scene format. uses a 2byte chunk number instead of a 4byte chunk name.

The Resource Interchange File Format (RIFF) is a generic meta-format for storing data in tagged chunks. ... Microsoft Corporation, (NASDAQ: MSFT, HKSE: 4338) is a multinational computer technology corporation with global annual revenue of US$44. ... International Business Machines Corporation (known as IBM or Big Blue; NYSE: IBM) is a multinational computer technology and consulting corporation headquartered in Armonk, New York, USA. The company is one of the few information technology companies with a continuous history dating back to the 19th century. ... When integers or any other data are represented with multiple bytes, there is no unique way of ordering of those bytes in memory or in a transmission over some medium, and so the order is subject to arbitrary convention. ... WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. ... AVI, an acronym for Audio Video Interleave, is a multimedia container format introduced by Microsoft in November 1992, as part of the Video for Windows technology. ... This article is about TIFF, the computer image format. ... Aldus Corporation (named after the 15th-century Venetian printer Aldus Manutius) was the inventor of the groundbreaking PageMaker software for the Apple Macintosh, a program that is generally credited with creating the desktop publishing (DTP) field. ... For the use of the term raster in radio regulation, see frequency raster. ... PostScript (PS) is a page description language and programming language used primarily in the electronic and desktop publishing areas. ... Musical Instrument Digital Interface, or MIDI, is an industry-standard electronic communication protocol that defines each musical note in an electronic musical instrument such as a synthesizer, precisely and concisely, allowing electronic musical instruments and computers to exchange data, or talk, with each other. ... PNG (Portable Network Graphics) is a bitmapped image format that employs lossless data compression. ... QuickTime is a multimedia framework developed by Apple Inc. ... MPEG-4 Part 14, formally ISO/IEC 14496-14:2003, is a multimedia container format standard specified as a part of MPEG-4. ... 3D Studio Max (sometimes called 3ds Max or just MAX) is a 3-dimensional vector graphics and animation program, written by Autodesk Media & Entertainment (formerly known as Discreet and Kinetix). ...

External links

• About Interchange File Format
• “EA IFF 85”: Standard for Interchange Format Files - the original IFF spec written by EA's Jerry Morrison (January 14, 1985)
• Interchange file format entries at File Extensions Encyclopedia
• Article on IFF
• Page about Amiga files formats and IFF variants
• Registry