Vidtoasf.exe Increases File Size When Converting AVI Files

ID: Q235945

This article discusses a Beta release of a Microsoft product. The information in this article is provided as-is and is subject to change without notice.

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The information in this article applies to:

SYMPTOMS

When you convert a low frame rate .avi file into a .asf file with the command line utility Vidtoasf.exe, the file size of the .asf file increases dramatically.


CAUSE

With low frame rate files, the first frame of the file is usually very large. This large frame must be sent within one second (the default) to the client. In order for this to be accomplished, the bit rate of the file is raised and filler is added to the file. The filler is what raises the bit rate and increases the file size.


RESOLUTION

When you use Vidtoasf.exe with low frame rate files, increase the lead time parameter from 1000 milliseconds (default) to a larger number. (Note: You probably won't see any benefit above 4000 milliseconds.) By increasing the lead time for the file, there is more time available to stream the first frame of the video when the file is streamed to a client. An example of this would be as follows:


vidtoasf.exe -in myfile.avi -out myfile.asf -leadtime 3000

Additional query words: netshow wms 


Keywords          : 
Version           : :4.0; winnt:3.0
Platform          : winnt 
Issue type        : kbprb

Last Reviewed: July 30, 1999