phoneGetGain

The phoneGetGain function returns the gain setting of the microphone of the specified phone's hookswitch device.

LONG WINAPI phoneGetGain(
  HPHONE hPhone,          
  DWORD dwHookSwitchDev,  
  LPDWORD lpdwGain        
);

Parameters

hPhone

A handle to the open phone device.

dwHookSwitchDev

The hookswitch device whose gain level is queried. The dwHookSwitchDev parameter can have only one bit set. This parameter uses one and only one of the PHONEHOOKSWITCHDEV_ Constants.

lpdwGain

A pointer to a DWORD containing the current gain setting of the hookswitch microphone component. The dwGain parameter specifies the volume 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.

Return Values

Returns zero if the request succeeds or a negative error number if an error occurs. Possible return values are:

PHONEERR_INVALPHONEHANDLE, PHONEERR_NOMEM, PHONEERR_INVALPOINTER, 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