IAudioPeakMeter interface (devicetopology.h)
The IAudioPeakMeter interface provides access to a hardware peak-meter control. The client obtains a reference to the IAudioPeakMeter interface of a subunit by calling the IPart::Activate method with parameter refiid set to REFIID IID_IAudioPeakMeter. The call to IPart::Activate succeeds only if the subunit supports the IAudioPeakMeter interface. Only a subunit object that represents a hardware peak meter will support this interface.
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 IAudioPeakMeter interface provides convenient access to the KSPROPERTY_AUDIO_PEAKMETER property of a subunit that has a subtype GUID value of KSNODETYPE_PEAKMETER. 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.
Inheritance
The IAudioPeakMeter interface inherits from the IUnknown interface. IAudioPeakMeter also has these types of members:
Methods
The IAudioPeakMeter interface has these methods.
| IAudioPeakMeter::GetChannelCount The GetChannelCount method gets the number of channels in the audio stream. (IAudioPeakMeter.GetChannelCount) |
| IAudioPeakMeter::GetLevel The GetLevel method gets the peak level that the peak meter recorded for the specified channel since the peak level for that channel was previously read. |
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Vista [desktop apps only] |
| Minimum supported server | Windows Server 2008 [desktop apps only] |
| Target Platform | Windows |
| Header | devicetopology.h |