phoneSetGain

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

LONG WINAPI 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. This parameter uses one and only one of the PHONEHOOKSWITCHDEV_ Constants.

dwGain

A pointer to a DWORD containing the new 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.

Requirements

  Windows NT/2000: Requires Windows NT 4.0 SP3 or later.
  Windows 95/98: Requires Windows 95 or later.
  Version: Requires TAPI 1.3 or later.
  Header: Declared in Tapi.h.
  Library: Use Tapi32.lib.

See Also

TAPI 2.2 Reference Overview, Supplementary Phone Service Functions, PHONE_REPLY