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CBasicAudio Class

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

This class handles the IDispatch interface component of the IBasicAudio interface and leaves the properties and methods of IBasicAudio pure virtual to be implemented by a derived filter class.

The CBasicAudio::GetIDsOfNames, CBasicAudio::GetTypeInfo, CBasicAudio::GetTypeInfoCount, and CBasicAudio::Invoke member functions are standard implementations of the IDispatch interface using the CBaseDispatch class (and a type library) to parse the commands and pass them to the pure virtual IBasicAudio methods.

DirectShow uses units of 100th of a decibel for the volume scale.

A value of 0 indicates maximum volume supported by the device.

A value of –10,000 is the minimum volume (normally silence).

Balance is expressed in the range –10,000 to 10,000, with 0 being neutral.

A negative balance value means that the right channel is attenuated by this dB value (that is, it is quieter).

A positive balance value means that the right channel is louder than the left; that is, the left channel is attenuated by the corresponding negative decibel value.

Member Functions

Member function Description

CBasicAudio

Constructs a CBasicAudio object.

Implemented INonDelegatingUnknown Methods

Method Description

NonDelegatingQueryInterface

Retrieves a specified reference-counted interface.

Implemented IDispatch Methods

Method Description

GetIDsOfNames

Maps a single member and an optional set of parameters to a corresponding set of integer dispatch identifiers, which can be used during subsequent calls to the CBasicAudio::Invoke member function.

GetTypeInfo

Retrieves a type-information object, which can retrieve the type information for an interface.

GetTypeInfoCount

Retrieves the number of type-information interfaces provided by an object.

Invoke

Provides access to properties and methods exposed by an object.

Requirements

Windows Embedded CE Windows CE 2.12 and later
Windows Mobile Windows Mobile Version 5.0 and later
Note Microsoft DirectShow applications and DirectShow filters have different include file and Library requirements
For more information, see Setting Up the Build Environment