Seeking in ASF Files

Seeking in ASF Files

The WM ASF Reader, through its IMediaSeeking interface, can perform very accurate temporal seeking on Windows Media–based content that has a temporal index. (All frame-indexed content also contains a temporal index.) Guaranteed frame-accurate seeking is not directly supported in the WM ASF Reader, but there is a way to do it if you require this functionality. First, use the Windows Media Format SDK directly to create an instance of the synchronous reader object, open the file, obtain the time stamp associated with a specified frame, and then use the DirectShow IMediaSeeking interface to seek to that time. The IVideoFrameStep interface does not support frame-accurate seeking of Windows Media–based content.

See Also

• Reading ASF Files in DirectShow