.AIFF

Audio Interchange File Format

Introduction

AIFF is an uncompressed audio format made by Apple in 1988, based on the IFF format from Electronic Arts. It holds the same kind of audio as a WAV file, but stores its samples big-endian, the byte order of the Motorola and PowerPC Macs it was made for. It is still common in music production on the Mac.

A variant, AIFF-C (usually .aifc), adds a compression type. Some software also writes .aif for plain AIFF.

Software

Structure

An AIFF file is one IFF FORM chunk whose form type is AIFF (or AIFC). Inside it are further chunks, each an ID, a big-endian length and that many bytes of data, padded to an even length. Two chunks are required: the common chunk COMM, which gives the channel count, number of sample frames, sample size and sample rate (as an 80-bit extended float), and the sound data chunk SSND, which holds the samples. Optional chunks carry markers, instrument settings, names and comments.

  1. 0FORM chunk ID, length, form type AIFF12 bytes
    1. 12COMM channels, frames, sample size, sample rate26 bytes
    2. 38SSND offset, block size, then the samplesvaries
    3. …MARK, INST, NAME and other optional chunksvaries
An AIFF file with its two required chunks first