The National Archives
Search our website
  • Search our website
  • Search our records
Image of software box and CD PRONOM
Welcome (PRONOM  home page) About PRONOM Add an entry
Search Help - opens in a new window Information resources - opens in a new window

*Details: File format summary



Search by keyword Search by file format Search by PUID Search by software Search by vendor Search by lifecycles Search by Migration Pathway

Details for:

Save as... XML | CSV Printer friendly version


Name Audio/Video Interleaved Format
Other names AVI (Generic)
Identifiers PUID:  fmt/5
Apple Uniform Type Identifier:  public.avi
MIME:  video/x-msvideo
Classification 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.
Orientation Binary
Byte order Little-endian (Intel)
Related file formats Has priority over Resource Interchange File Format (RIFF)  
Technical Environment  
Supported until  
Format Risk  
Developed by None.
Supported by None.
Source Digital Preservation Department / The National Archives
Source date 11 Mar 2005
Source description 08/2023 (v.113) - Added priority over fmt/1886 (Resource Interchange Format (RIFF)) and simplified internal signature to reduce identification tool processing time. Submitted by Preservica and New York Public Libraries.
Last updated 14 Aug 2023
Top of page Top of page
The National Archives Newsletter Icon

Send me The National Archives’ newsletter

A monthly round-up of news, blogs, offers and events.