Format

Audio/Video Interleaved Format

Summary

Name

Audio/Video Interleaved Format

Identifiers

• PUID: fmt/5
• Apple Uniform Type Identifier: public.avi
• MIME: video/x-msvideo

Format type

• Audio
• Video

Disclosure

Full

Description

Audio/Video Interleaved Format (AVI) is a chunk-based video format developed by Microsoft, based on the generic Resource Interchange File Format (RIFF) specification developed by Microsoft and IBM. Structurally, an AVI file is composed of a number of chunks, each comprising a four character code chunk identifier, the chunk size, and the chunk data. It comprises a RIFF header with an AVI data type identifier, followed by a series of chunks. Every file must include two List chunks. The first List chunk is the main AVI header chunk, which contain one or more Stream Header chunks, one for each data stream, describing the format of the data streams. The second LIST chunk is the ‘movi’ chunk, which contains the actual data for the audio and video data streams. Other optional chunks are also allowed. The format supports a wide variety of compressed and uncompressed video encodings, but all audio streams are stored in Microsoft’s Waveform Audio format.

File extensions

avi

Source

Digital Preservation Department / The National Archives

Relationships

Has priority over

• Resource Interchange File Format (RIFF)

Internal signatures

Changelog

• Updated in V114

  Release date

  22 August 2023

  Audio/Video Interleaved Format: Signature simplified to increase identification tool processing time. Added priority over fmt/1886. Submitted by Preservica and New York Public Libraries.