Sustainability of Digital Formats
 Planning for Library of Congress Collections

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Identification and description

Full name	Waveform Audio File Format (WAVE) with Linear PCM bitstream
Description	WAVE file format with default bitstream encoding, which is Microsoft (linear) Pulse Code Modulation (PCM) format.
Production phase	Used primarily as a initial/middle state format as a master file for audio captured live digitally or from analog sources.
Relationship to other formats
Subtype of	WAVE,
Subtype of	RIFF, Resource Interchange File Format for Windows 3.1
Has subtype	WAVE_LPCM_BWF, Broadcast Wave
Contains	LPCM, Linear PCM

Local use

LC experience or existing holdings	Used as the best digital format for most audio converted for American Memory and the Digital A/V Prototype.
LC preference	Preferred format for sound recordings.

Sustainability factors

Disclosure	Fully documented. Proprietary format developed by Microsoft and IBM as part of the Resource Interchange File Format (RIFF) for Windows 3.1. Incorporated into WAVE_LPCM_BWF, standardized by European Broadcast Union.
Documentation	Multimedia Programming Interface and Data Specifications 1.0. IBM Corporation and Microsoft Corporation, August 1991. Included in Microsoft Windows Multimedia Programmer's Reference, 1991. Available online, e.g., at http://www.tactilemedia.com/info/MCI_Control_Info.html.
Adoption	Widely used.
Licensing and patents	No special issues.
Transparency	See LPCM
Self-documentation	Can include Fact Chunks with additional metadata, Playlist Chunks defining the playing order and linking to cue points, and Associated Data Chunks containing labels, notes and related text (which can be country/language dependent). Refinements of the WAVE format used in the broadcast industry include metadata chunks appropriate for the interchange of radio programs and other audio content.
External dependencies	None
Technical protection considerations	None

Quality and functionality factors

Sound
Normal rendering	Good support.
Fidelity (high audio resolution)	Fidelity for LPCM is enhanced by higher sample rates and sample sizes. Audio CDs use a sample rate of 44.1 kHz and a sample size of 16 bits/sample. The preferred characteristics for audio conversion from LPs in M/B/RS is 96 kHz with 24-bit samples. In the WAVE format syntax, the limits on sample rate (a 32-bit integer, up to 0xFFFFFFFF, or 4,294,967,295) and sample size (a 16-bit integer, up to 65,535 bits/sample) are high enough to place no practical limit on fidelity. In practice, as 24-or 32-bit sample sizes and higher sampling rates (DVD Audio supports up to 192Khz) become more common, the overall limit on file size, set by individual computer operating systems, becomes a constraint. With 192kHz sampling and 24 bits/sample, about half an hour of stereo can be stored in a 4 Gbyte file (the limit on Windows 2000).
Multiple channels	Not beyond stereo.
Functionality beyond normal rendering	None

File type signifiers

Tag	Value	Note
Filename extension	See note.	See WAVE
Internet Media Type	See note.	See WAVE
Magic numbers	See note.	See WAVE
Microsoft WAVE format registry	0x0001	From Microsoft registry.

Notes

General
History	Format created by Microsoft and introduced with Windows 3.1. Adopted as basis for European Broadcasting Union (EBU) WAVE_LPCM_BWF standard.

Format specifications

• Multimedia Programming Interface and Data Specifications 1.0. August 1991 (http://www.tactilemedia.com/info/MCI_Control_Info.html). . Issued jointly by IBM Corporation and Microsoft Corporation. (Online at several locations, e.g., ; http://www.seanet.com/Users/matts/riffmci/riffmci.htm)
• Microsoft Corporation. Microsoft Windows Multimedia Programmer's Reference. Redmond, WA: Microsoft Press, 1991. Chapter 8.

Useful references