Sustainability of Digital Formats
 Planning for Library of Congress Collections

Format Description Categories >> Browse Alphabetical List>> Back

Identification and description

Full name	AVI (Audio Video Interleaved), Motion JPEG Video Codec
Description	File format that wraps an MJPEG video bitstream with other data chunks, e.g., audio, in an AVI wrapper
Production phase	Generally a middle-state format (often used as the video source when producing lower-resolution streaming versions).
Relationship to other formats
Subtype of	AVI,
Contains	MJPEG, Video codec
May contain	WAVE, Audio (interleaved with video)
May contain	MP3_CBR, (constant bit rate) audio (interleaved with video)

Local use

LC experience or existing holdings
LC preference	See AVI.

Sustainability factors

Disclosure	See AVI and MJPEG
Documentation	See AVI and MJPEG
Adoption	AVI is widely adopted for video production and filemaking; commentator John McGowan writes, "Most PC video capture and editing systems capture video to AVI files using Motion JPEG video compression."
Licensing and patents	See AVI.
Transparency	See MJPEG, especially the note in Description from a newsgroup writer pertaining to the difference between JPEG and MJPEG.
Self-documentation	See AVI and MJPEG, especially the note in Description from a newsgroup writer pertaining to the difference between JPEG and MJPEG.
External dependencies	See AVI.
Technical protection considerations	See AVI.

Quality and functionality factors

Moving Image
Normal rendering	Good support.
Clarity (high image resolution)	Moderate to very good, given that this is a format typically used for compression and that most AVI implementations do not support interlaced video. Outcome will depend on the type and extent of compression, and the encoder used. High resolution work is limited in the Windows environment due to file size limits (2 GB with FAT 16 technology; theoretical 8 GB with later technologies). Note that use of OpenDML extensions to AVI would permit MJPEG with interlaced video and other features that increase clarity.
Functionality beyond normal rendering	See AVI

File type signifiers

Tag	Value	Note
Filename extension	avi
Internet Media Type	See related format.	See AVI
Magic numbers	See related format.	See AVI
Microsoft FOURCC	MJPG	See, for example the archived version of the Microsoft registry of FOURCC and WAVE codes mounted by IANA.

Notes

General
History

Format specifications

• See Disclosure under Sustainability factors.

Useful references

URLs

• John McGowan's AVI Overview (http://www.jmcgowan.com/avi.html).
• John McGowan's AVI Audio and Video Codecs (http://www.jmcgowan.com/avicodecs.html).
• Archived snapshots of "Microsoft registry" at Internet Archive.
  • Microsoft registry, as of December 2001 (http://web.archive.org/web/20100922105522/http://www.microsoft.com/whdc/archive/fourcc.mspx).
  • Microsoft registry, as of June 2003 (http://web.archive.org/web/20100620230818/http://msdn.microsoft.com/en-us/library/ms867195.aspx).
• WAVE and AVI Codec Registries (Historic Registry) (http://www.iana.org/assignments/wave-avi-codec-registry/wave-avi-codec-registry.xml). Former "Microsoft registry" as archived by IANA in 2008.
• Gary Kessler's File Signatures Table (http://www.garykessler.net/library/file_sigs.html).