Sustainability of Digital Formats: Planning for Library of Congress Collections

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Windows Media 9 Lossless Audio Codec

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name Windows Media 9 Lossless Audio Codec
Description Audio bitstream produced by the Windows Media 9 lossless audio codec.
Production phase Used for middle-state purposes, e.g., archiving of high-quality files.
Relationship to other formats
    Used by WMA_WMA9_LL, Windows Media Audio file with WMA9_LL codec

Local use Explanation of format description terms

LC experience or existing holdings  
LC preference See WMA.

Sustainability factors Explanation of format description terms

Disclosure Proprietary. Developed by Microsoft.
    Documentation Specifications not disseminated.
Adoption Extent of adoption is not known; the WMA file format is widely adopted. The lossless codec is specialized and may not see wide adoption.
    Licensing and patents See ASF for link to pages covering licensing of Windows Media and the Advanced Systems Format.
Transparency Depends upon algorithms and tools to read; will require sophistication to build tools.
Self-documentation Not applicable
External dependencies None
Technical protection considerations Not applicable

Quality and functionality factors Explanation of format description terms

Sound
Normal rendering Good support.
Fidelity (high audio resolution) From the codecs page at the Microsoft Windows Media web site (consulted September 7, 2010): "This codec is a great codec to use for archiving CD collections. Although the compression ratio achieved with this codec is lower than the ratio achieved with other Windows Media Audio 9 codecs, it is still more efficient than direct copying of the digital media content. Using this codec, content will be compressed at a 2:1 or 3:1 ratio depending on the complexity of the original. The audio quality of content compressed using this codec is the best of all Windows Media codecs."
Multiple channels Not supported [?]
Functionality beyond normal rendering Not applicable

File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension Not applicable.   
Internet Media Type Not applicable.   
Magic numbers Not applicable.   

Notes Explanation of format description terms

General  
History  

Format specifications Explanation of format description terms


Useful references

URLs


Last Updated: Tuesday, 21-Feb-2017 08:55:47 EST