IAudioChannelConfig Interface

IAudioChannelConfig Interface

The IAudioChannelConfig interface provides access to a hardware channel-configuration control. The client obtains a reference to the IAudioChannelConfig interface of a subunit by calling the IPart::Activate method with parameter refiid set to REFIID IID_IAudioChannelConfig. The call to IPart::Activate succeeds only if the subunit supports the IAudioChannelConfig interface. Only a subunit object that represents a hardware channel-configuration control will support this interface.

A client of the IAudioChannelConfig interface programs a hardware channel-configuration control by writing a channel-configuration mask to the control. The mask specifies the assignment of audio channels to speakers. For more information about channel-configuration masks, see the following:

• The discussion of the KSPROPERTY_AUDIO_CHANNEL_CONFIG property in the Windows DDK documentation.
• The white paper titled "Audio Driver Support for Home Theater Speaker Configurations" at the Audio Device Technologies for Windows Web site.

Most Windows audio adapter drivers support the Windows Driver Model (WDM) and use kernel-streaming (KS) properties to represent the hardware control parameters in subunits (referred to as KS nodes). The IAudioChannelConfig interface provides convenient access to the KSPROPERTY_AUDIO_CHANNEL_CONFIG property of a subunit that has a subtype GUID value of KSNODETYPE_3D_EFFECTS, KSNODETYPE_DAC, KSNODETYPE_VOLUME, or KSNODETYPE_PROLOGIC_DECODER. To obtain the subtype GUID of a subunit, call the IPart::GetSubType method. For more information about KS properties and KS node types, see the Windows DDK documentation.

IAudioChannelConfig inherits from the IUnknown interface. In addition to the methods inherited from IUnknown, IAudioChannelConfig supports the following methods.

Requirements

Client: Windows Vista

Header: Include Devicetopology.h.

See Also

• DeviceTopology API
• IPart::Activate