Sustainability of Digital Formats: Planning for Library of Congress Collections
Sustainability of Digital Formats: Planning for Library of Congress Collections |
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | Windows Media 9 Lossless Audio Codec |
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| 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 |
| LC experience or existing holdings | |
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| LC preference | See WMA. |
| Disclosure | Proprietary. Developed by Microsoft. |
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| 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 |
| Sound | |
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| 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 |
| Tag | Value | Note |
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| Filename extension | Not applicable. | |
| Internet Media Type | Not applicable. | |
| Magic numbers | Not applicable. |
| General | |
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| History |
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