Re: How to programmatically check and fix asf files like asfcheck.exe

From: Alessandro Angeli [MVP::DigitalMedia] (nobody_at_nowhere.in.the.net)
Date: 04/28/04 

Date: Wed, 28 Apr 2004 10:20:33 +0200

Justin Engelman wrote:

> Hello,
> How can I programmatically (preferrably from VB.NET)
> check for wma or wmv file corruption and try to fix
> errors like the WMTools ASFCheck command line utility
> does? Ideally I think it would be done using the Encoder
> SDK since that has an interface I can use from VB, unlike
> the Format SDK which requires some complex C++ (and I
> still have a lot to learn about C++ and the Windows SDK).
> Is this possible?
>
> Also, if anyone knows what exactly the ASFCheck utility
> is looking for to see if a file is corrupt and how it
> tries to fix the problem, could you please explain? I
> can't find any detailed documentation on MSDN or anywhere
> else online for ASFCheck.

ASFCheck is old and pre-dates the WMFSDK and anything based
on it (WME9 for example). There is no library to perform a
check because that is not something that can be done using
the WMFSDK.

ASFCheck scans the ASF structure itself and, since the ASF
syntax forces a given pattern in the file, it can determine
whether the file is corrupt and fix it (only to some
extent).

You can get the ASF specs from http://www.microsoft.com/asf
and scan the file yourself in any language that can read
binary files. It is not too difficult but not the easiest of
things either. Finding a reliable error detection and error
correction algorithm is a whole other story. 

-- 
/**
 * Alessandro Angeli
 *
 * MVP :: Digital Media
 *
 * a dot angeli at biosys dot net
 */

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