CBasicAudio Class (Compact 2013)

3/26/2014

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

Header	dshow.h, Streams.h
Library	ole32.lib, Ole32auth.lib, Strmbase.lib, Strmiids.lib, uuid.lib

See Also

Reference

DirectShow Classes