CBasicAudio Class
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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 |
|---|---|
Constructs a CBasicAudio object. |
Implemented INonDelegatingUnknown Methods
| Method | Description |
|---|---|
Retrieves a specified reference-counted interface. |
Implemented IDispatch Methods
| Method | Description |
|---|---|
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. |
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Retrieves a type-information object, which can retrieve the type information for an interface. |
|
Retrieves the number of type-information interfaces provided by an object. |
|
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 |