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Exposing Custom Audio Property Sets

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DirectSound supports the use of custom properties on sound cards and provides an IKsPropertySet interface for this purpose.

Note   Header files Dsound.h and Ksproxy.h define similar but incompatible versions of the IKsPropertySet interface. DirectSound applications should use the version defined in Dsound.h. The DirectSound version of IKsPropertySet is defined in the DirectSound reference pages in the Microsoft Windows SDK documentation. For the KSProxy version, see IKsPropertySet.

Custom audio property sets are enabled by default in Windows 98 Second Edition and Windows Me, and in Windows XP and later. By default, DirectSound ignores custom property sets in Windows 2000, and in Windows Server 2003 and later server versions of Windows. For DirectSound to recognize a custom property set in one of these operating systems, users must first enable custom property sets on their systems.

For example, to enable custom audio property sets in Windows 2000:

  1. In Control Panel, double-click the Sounds and Multimedia icon (or just run mmsys.cpl).

  2. On the Audio tab, select the appropriate preferred device in the Sound Playback list.

  3. Click the Advanced button.

  4. On the Performance tab, slide the Hardware Acceleration slider to Full.

  5. Click Apply.

DirectSound is now enabled to pass custom property sets to the driver.

Four settings are available on the Hardware Acceleration slider:

  • None

  • Basic

  • Standard

  • Full

Custom property sets are enabled only when the slider is set to Full. For more information, see DirectSound Hardware-Acceleration and SRC Sliders.