Microsoft KB Archive/944436

= The DVD playback volume in Windows Media Player or in a Windows Media Center application is not loud enough on a Windows Vista-based portable computer =

Article ID: 944436

Article Last Modified on 12/20/2007

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APPLIES TO


 * Windows Vista Home Premium
 * Windows Vista Ultimate
 * Windows Vista Home Premium 64-bit Edition
 * Windows Vista Ultimate 64-bit Edition

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Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

322756 How to back up and restore the registry in Windows XP and Windows Vista



SYMPTOMS
You insert a DVD disk to watch a movie on a Windows Vista-based portable computer. You use Windows Media Player (Wmplayer.exe) or an application in Windows Media Center (Ehshell.exe) to watch the movie. However, the overall volume seems to be too low. For example, when you set maximum gain on all volume controls that are available in the audio mixer, system sounds and CD music playback are loud enough. However, DVD playback volume is still not loud enough.



CAUSE
This problem occurs because the default playback decoding mode of the AC-3 (Dolby Digital) streams is set to Normal mode. For DVD playback on portable computers, the default playback decoding mode should be set to Laptop Mode (RF decoding mode). The Laptop Mode (RF decoding mode) provides an additional increase in gain of 11 dB.



RESOLUTION
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

For 32-bit versions of Windows Vista Home Premium and of Windows Vista Ultimate
To enable this hotfix, you must create the following registry entry on the portable computer:

dolby_rf_on

To do this, follow these steps:  Click Start, click Run, type regedit, and then click OK. Locate and then click the following registry subkey:

HKEY_LOCAL_MACHINE\Software\Microsoft\Scrunch\CodecPack\MSDVD

Note If you cannot locate the registry subkey, go to step 3 to create the registry subkey. If you can locate the registry subkey, go to step 6. Right-click the Microsoft registry subkey, point to New, click Key, type Scrunch, and then press ENTER. Right-click the Scrunch registry subkey, point to New, click Key, type CodecPack, and then press ENTER. Right-click the CodecPack registry subkey, point to New, click Key, type MSDVD, and then press ENTER. On the Edit menu, point to New, and then click DWORD Value.</li> In the details pane, type the following new value, dolby_rf_on, and then press ENTER.</li> Right-click dolby_rf_on, and then click Modify.</li> In the Edit DWORD Value dialog box, under Base, click Decimal.</li> In the Value data box, type the value 1, and then click OK.

Note Only &quot;0&quot; and &quot;1&quot; are supported values. If the dolby_rf_on registry entry contains any other value, the decoder ignores the value and uses the default value. If the registry entry is set to &quot;1,&quot; the Laptop Mode is used as the default on the computer.</li> Close Registry Editor.</li> Restart the Windows Media Player or the Windows Media Center application.</li></ol>

For 64-bit versions of Windows Vista Home Premium and of Windows Vista Ultimate
To enable this hotfix, you must create the following registry entry on the portable computer:

dolby_rf_on

To do this, follow these steps: <ol> Click Start, click Run, type regedit, and then click OK.</li> Locate and then click the following registry subkey:

HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Scrunch\CodecPack\MSDVD

Note If you cannot locate the registry subkey, go to step 3 to create the registry subkey. If you can locate the registry subkey, go to step 6.</li> Right-click the Microsoft registry subkey, point to New, click Key, type Scrunch, and then press ENTER.</li> Right-click the Scrunch registry subkey, point to New, click Key, type CodecPack, and then press ENTER.</li> Right-click the CodecPack registry subkey, point to New, click Key, type MSDVD, and then press ENTER.</li> On the Edit menu, point to New, and then click DWORD Value.</li> In the details pane, type the following new value, dolby_rf_on, and then press ENTER.</li> Right-click dolby_rf_on, and then click Modify.</li> In the Edit DWORD Value dialog box, under Base, click Decimal.</li> In the Value data box, type the value 1, and then click OK.

Note Only &quot;0&quot; and &quot;1&quot; are supported values. If the dolby_rf_on registry entry contains any other value, the decoder ignores the value and uses the default value. If the registry entry is set to &quot;1,&quot; the Laptop Mode is used as the default on the computer.</li> <li>Close Registry Editor.</li> <li>Restart the Windows Media Player or the Windows Media Center application.</li></ol>

Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Prerequisites
No prerequisites are required.

Restart requirement
You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any previously released hotfixes.

File information
The English version of this hotfix 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.

Windows Vista, 64-bit versions
<div class="status_section">

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

Additional query words: audio decoder, dolby digital, AC-3, DVD playback volume, RF

Keywords: kbexpertiseinter kbhotfixserver kbqfe KB944436

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