An audio application cannot play the latest non-Pulse Code Modulation (PCM) or encrypted PCM and non-PCM audio formats even after you install a High Definition Audio function driver on a Windows Vista-based or Windows Server 2008-based computer

You install a High Definition (HD) Audio function driver on a Windows Vista-based or Windows Server 2008-based computer. The driver can expose multiple non-Pulse Code Modulation (PCM) audio formats and some PCM or non-PCM audio formats that are encrypted.

However, you may notice that the audio application cannot play the following formats:

• The latest non-PCM formats, such as Dolby True HD
• Both PCM and non-PCM audio formats that are encrypted

The audio formats that are mentioned in the "Symptoms" section are expressed in a KSDATARANGE_AUDIO structure with a unique SubFormat GUID. The GUID comes from the WAVEFORMATEXTENSIBLE structure.

When the audio application selects a specific audio format to transfer stream data, the audio miniport driver should see the corresponding KSDATAFORMAT structure that contains the specific GUID and other parameters in the miniport’s handlers. For example, the audio miniport driver should see the NewStream() parameter. When the audio driver encounters these parameters, the driver takes some action, based on the specific GUID.

However, in Windows Vista-based or Windows Server 2008-based computers, the system audio stack (Portcls.sys) may pass a KSDATAFORMAT instance with a different GUID to the WaveRT miniport’s NewStream() parameter.

For example, there can be two data ranges that have the same sample rates, but the data ranges have a different number of channels. In this case, the system may detect one data range that is the first data range that matches the sample rate and the sample bit in the array. However, the channel number is incorrect.

Therefore, the audio driver does not obtain the correct data format. Because the driver does not obtain the correct data format, the audio driver cannot function correctly with regard to the audio format that was selected in the application, and the function fails.

Hotfix information

A supported hotfix is 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 the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if 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. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the “Hotfix Request” page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.

Prerequisites

No prerequisites are required to install this hotfix.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other 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 and Windows Server 2008 file information notes

• The files that apply to a specific product, milestone (RTM, SPn) can be identified by examining the file version numbers as shown in the following table:
  Collapse this tableExpand this table

  Version	Product	Milestone	Service branch
  6.0.600 0 . 20 xxx	Windows	RTM	LDR
  6.0.600 1 . 22 xxx	Windows Vista SP1 and Windows Server 2008 SP1	SP1	LDR

• Service Pack 1 is integrated into Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxxx version number.
• The MANIFEST files (.manifest) and MUM files (.mum) installed for each environment are listed separately. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files (attributes not listed) are signed with a Microsoft digital signature.

For all supported 32-bit versions of Windows Server 2008 and of Windows Vista

For all supported 64-bit versions of Windows Server 2008 and of Windows Vista

For all supported Itanium-based versions of Windows Server 2008

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about KSDATARANGE_AUDIO, visit the following Web site:For more information about WAVEFORMATEXTENSIBLE, visit the following Web site:For more information about KSDATAFORMAT, visit the following Web site:For more information about WaveRT, visit the following Web sites:

Additional file information for Windows Server 2008 and for Windows Vista

Additional files for all supported 32-bit versions of Windows Server 2008 and of Windows Vista

Additional files for all supported 64-bit versions of Windows Server 2008 and of Windows Vista

Additional files for all supported Itanium-based versions of Windows Server 2008