IFF

Revision as of 15:01, 22 October 2013

Overview

IFF (Interchange File Format) is a file format introduced by Electronic Arts on the Commodore Amiga computer. Its structure is similar to RIFF or PNG, using various self-contained chunks to contain different data. Multi-byte numeric values are big-endian.

Although IFF is most commonly used as an image format (using the file extension .iff), it can actually hold a lot of different data types. Some examples of IFF files are

• ILBM Interleaved bitmap image
• XMI XMidi music files
• 8SVX audio sample data
• SX2 Propellerhead Reason NN-XT patches
• ANIM

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

• Erlang BEAM compiled modules^[1][2]: 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
• EA IFF

References

1. ↑ http://www.erlang.org/doc/man/beam_lib.html
2. ↑ http://www.erlang.se/~bjorn/beam_file_format.html

Resources

• The original EA spec (Another copy at textfiles.com)
• IFF chunk registry, defining all known chunks
• IFF Source Code
• REWiki: .IFF
• IFF File Format Summary
• 1994 "advanced music formats" discussion that covers some IFF formats