Creating ASF Files in DirectShow (DirectShow)

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

This section describes how to use the DirectShow WM ASF Writer filter to create files in Advanced Systems Format (ASF). ASF is a container format that can contain any type of compressed or uncompressed data. Windows Media Format files are ASF files that use certain codecs as specified in the Windows Media Format Software Development Kit (SDK). These files use the extensions ".wma" for Windows Media Audio files and ".wmv" for Windows Media Video files.

This topic contains the following sections:

Using Windows Media in DirectShow