ASF File Features
[The feature associated with this page, Windows Media Format 11 SDK, is a legacy feature. It has been superseded by Source Reader and Sink Writer. Source Reader and Sink Writer have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Source Reader and Sink Writer instead of Windows Media Format 11 SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The primary purpose of the Windows Media Format SDK is to provide support for encapsulating digital media data in Advanced Systems Format (ASF) files and delivering the media to a client application. Delivery scenarios can vary widely from application to application, but all use the ASF file structure between authoring and delivery. ASF files conform to a well defined but very flexible structure. For more information about the ASF file structure, see Overview of the ASF Format.
Detailed information about the data in an ASF file is provided in the ASF specification, which you can download from the Microsoft Web site.
The Windows Media Format SDK provides support for the features of the ASF specification mostly through the profile that is used to create a file. For more information about profiles, see Profiles.
The following features are discussed in this section.
- Audio and Video Streams
- Image Streams
- Arbitrary Streams
- Script Commands
- Data Unit Extensions
- SMPTE Time Code Support
- Mutual Exclusion
- Stream Prioritization
- Bandwidth Sharing
- Indexes
- Markers
- Reader Response to ASF Features
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