Article ID: 284094 - Last Review: November 17, 2003 - Revision: 2.2
The Difference Between ASF and WMV/WMA Files
This article was previously published under Q284094
The only difference between ASF files and WMV or WMA files are the file extensions and the MIME types. The MIME type for a WMV file is video/x-ms-wmv, and for WMA it is audio/x-ms-wma. The MIME type for ASF is video/x-ms-asf. The basic internal structure of the files is identical.
The change in extensions was made to make it easier for an application to identify the content of a media file. A .wma file extension designates a file containing only audio. A .wmv extension designates a file containing both video and audio.
- Microsoft Windows Media Services 4.1
- Microsoft Windows Media Encoder 7.0
- Microsoft Windows Media Encoder 7.1