Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
|
|
|
|
| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| 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 |
| LC experience or existing holdings | |
| LC preference | See WMA |
| Disclosure | Proprietary. Developed by Microsoft. |
| Documentation | Specifications not disseminated. Some descriptions and software development kits available from Microsoft. |
| Adoption | Not known to the compilers of this document; the WMA file format is widely adopted. The lossless codec is specialized and may not see wide adoption. |
| Licensing and patent claims | 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 |
| Normal rendering | Good support. |
| Fidelity (support for high audio resolution) | From the codecs page at the Microsoft Windows Media web site: "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." |
| Support for multiple sound channels | Not supported [?] |
| Functionality beyond normal rendering | Not applicable |
| Tag type | Value | Note |
| Filename Extension | Not applicable | |
| Internet Media Type | Not applicable | |
| Magic numbers | Not applicable |
| General | |
| History |
URLs
Print
Print
|
|