Sustainability of Digital Formats: Planning for Library of Congress Collections

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RIFF (Resource Interchange File Format)

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name Resource Interchange File Format (RIFF)

RIFF (Resource Interchange File Format) is a tagged file structure for multimedia resource files. Strictly speaking, RIFF is not a file format, but a file structure that defines a class of more specific file formats, some of which are listed here as subtypes. The basic building block of a RIFF file is called a chunk. Chunks are identified by four-character codes and an application such as a viewer will skip chunks with codes it does not recognize. The basic chunk is a RIFF chunk, which must start with a second four-character code, a label that identifies the particular RIFF "form" or subtype. Applications that play or render RIFF files may ignore chunks with labels they do not recognize. Chunks can be nested. The RIFF structure is the basis for a few important file formats, but has not been used as the wrapper structure for any file formats developed since the mid 1990s.

Production phase Not applicable. Depends on subtype.
Relationship to other formats
    Has subtype WAVE, WAVE Audio File Format
    Has subtype AVI, Audio Video Interleaved
    Has subtype DLS_1_1b, Downloadable Sounds, Version 1.1b
    Has subtype RMID, RIFF-based MIDI File Format
    Other WebP, WebP

Local use Explanation of format description terms

LC experience or existing holdings LC has experience with some RIFF subtypes. See WAVE_LPCM, AVI.
LC preference Depends on subtype. See WAVE_LPCM, AVI, and RMID.

Sustainability factors Explanation of format description terms

Disclosure Fully documented. Documentation freely available. Proprietary format developed by Microsoft and IBM for Windows 3.1.

Multimedia Programming Interface and Data Specifications 1.0. IBM Corporation and Microsoft Corporation, August 1991. Available online, e.g., at

Multimedia Data Standards Update April 15, 1994 at

Adoption Certain subtypes are widely adopted. In particular, see WAVE and AVI.
    Licensing and patents None
Transparency RIFF itself is transparent as a wrapper. Transparency of subtypes is determined by the encoding of the wrapped content. See subtypes.
Self-documentation The RIFF format allows for nested chunks. Defined within the RIFF specifications is an INFO List chunk, designed to hold various specific metadata elements. The extent to which INFO List chunks have been used to embed descriptive and technical metadata is not clear. In addition, new chunk types can be defined. For example, Broadcast WAVE (WAVE_BWF_1 and WAVE_BWF_2) adds a "Broadcast Audio Extension" chunk to hold the minimum information considered necessary for broadcast applications.
External dependencies None.
Technical protection considerations None.

Quality and functionality factors Explanation of format description terms

Not applicable Quality and functionality factors not directly applicable; depends on subtype. Certain subtypes are widely adopted. In particular, see WAVE and AVI.

File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension Not applicable.  Depends on subtype.
Wikidata Title ID Q1196805

Notes Explanation of format description terms

History The RIFF format specifications were first developed by IBM and Microsoft, and published by in 1991 in Microsoft Windows Multimedia Programmer's Reference. At that time, Microsoft indicated that the RIFF structure was the preferred structure for new multimedia formats. However, the RIFF structure does not appear to have been adopted for any new file formats established since the early 1990s. Microsoft now uses ASF (Advanced Systems Format) as a wrapper for media content. As of August 2004, Microsoft Windows Media player supported the most widely adopted RIFF-based files: WAVE, AVI and RMID, but documentation makes little mention of RIFF per se.

Format specifications Explanation of format description terms

Useful references


Books, articles, etc.

Last Updated: 05/18/2023