Sustainability of Digital Formats: Planning for Library of Congress Collections

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Windows Media 9 Professional 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 Professional Audio Codec
Description Audio bitstream produced by the Windows Media 9 professional audio codec.
Production phase Generally used in files that represent a final-state format for end-user delivery.
Relationship to other formats
    Used by WMA_WMA9_PRO, Windows Media Audio file with WMA9_PRO 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.
    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) Better fidelity than WMA_WMA9, not as good as WMA_WMA9_LL. From the codecs page at the Microsoft Windows Media web site (consulted September 7, 2010): "This codec captures full-resolution 24-bit/96-kilohertz (kHz) audio . . . for streaming or download-and-play delivery at 128 to 768 Kbps." This codec supports variable bit rate coding that enables higher quality at smaller file sizes.
Multiple channels From the codecs page at the Microsoft Windows Media web site(consulted September 7, 2010): "For use in scenarios that require digital surround-sound. This codec captures audio in stereo or 5.1 channel (or even 7.1) surround . . . ."
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