phoneSetGain

The phoneSetGain function sets the gain of the microphone of the specified hookswitch device to the specified gain level.

LONG phoneSetGain(
  HPHONE hPhone,          
  DWORD dwHookSwitchDev,  
  DWORD dwGain            
);
 

Parameters

hPhone

A handle to the open phone device. The application must be the owner of the phone.

dwHookSwitchDev

The hookswitch device whose microphone's gain is to be set. The dwHookswitchDev parameter can only have a single bit set. This parameter uses the following PHONEHOOKSWITCHDEV_ constants:

PHONEHOOKSWITCHDEV_HANDSET

The phone's handset.

PHONEHOOKSWITCHDEV_SPEAKER

The phone's speakerphone or adjunct.

PHONEHOOKSWITCHDEV_HEADSET

The phone's headset.

dwGain

A pointer to a DWORD-sized location containing the current gain setting of the device. The dwGain parameter specifies the gain level of the hookswitch device. This is a number in the range 0x00000000 (silence) to 0x0000FFFF (maximum volume). The actual granularity and quantization of gain settings in this range are service provider-specific. A value for dwGain that is out of range is set to the nearest value in the range.

Return Values

Returns a positive request identifier if the function is completed asynchronously or a negative error number if an error occurs. The dwParam2 parameter of the corresponding PHONE_REPLY message is zero if the function succeeds or it is a negative error number if an error occurs. Possible return values are:

PHONEERR_INVALPHONEHANDLE, PHONEERR_NOMEM, PHONEERR_NOTOWNER, PHONEERR_RESOURCEUNAVAIL, PHONEERR_INVALPHONESTATE, PHONEERR_OPERATIONFAILED, PHONEERR_INVALHOOKSWITCHDEV, PHONEERR_UNINITIALIZED, PHONEERR_OPERATIONUNAVAIL.

QuickInfo

  Version: Use TAPI version 1.4 and later.
  Header: Declared in tapi.h.
  Import Library: Link with tapi32.lib.

See Also

TAPI Reference Overview, Supplementary Phone Services Functions, PHONE_REPLY