Microsoft KB Archive/925039

= FIX: You may hear noise when you use DirectShow to play an MP3 file on a Windows CE .NET 4.2-based device =

Article ID: 925039

Article Last Modified on 11/8/2006

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APPLIES TO


 * Microsoft Windows CE .NET 4.2

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SYMPTOMS
Consider the following scenario. On a Microsoft Windows CE .NET 4.2-based device, you use Microsoft DirectShow to play an MP3 file. During playback, another application starts a thread that has a higher priority than DirectShow. In this scenario, you may hear noise during playback.



CAUSE
This problem occurs when the MP3 decoder file buffer is not large enough.



Software update information
A supported software update is now available from Microsoft as Windows CE .NET 4.2 Platform Builder Monthly Update (October 2006). You can confirm this by scrolling to the &quot;File information&quot; section of this article. The package file name contains the product version, date, Knowledge Base article number, and processor type. The package file name format is:

Product version-yymmdd-kbnnnnnn-processor type

For example: Wincepb50-060503-kb917590-armv4i.msi is the ARMV4i Windows CE 5.0 Platform Builder fix that is documented in KB article 917590 and that is contained in the May 2006 monthly update. To resolve this problem immediately, click the following article number for information about obtaining Windows CE Platform Builder and core operating system software updates:

837392 How to locate core operating system fixes for Microsoft Windows CE Platform Builder products

Prerequisites
This software update is supported only if all previously issued software updates for this product have also been applied.

Restart requirement
After you apply this software update, you must perform a clean build of the whole platform. To clean the platform, click Clean on the Build menu. To build the platform, click Build Platform on the Build menu. You do not have to restart the computer after you apply this software update.

Software update replacement information
This software update does not replace any other software updates.

File information
The English version of this software update package has the file attributes or the later file attributes that are listed in the following table.

The English version of this software update package has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
After you apply the software update that is described in this article, original equipment manufacturers (OEMs) can configure the minimum allowed size for MP3 DirectX Media Object (DMO) buffer requests. To do this, OEMs must add or modify the following registry entry in their registry configuration files:

Note The MinBufferSize value is a hexadecimal value that represents the minimum allowed size, in bytes, for MP3 DMO buffer requests. The default hexadecimal value of 4000 equals 16384 bytes, or 16 KB.

