PIBIO_ENGINE_QUERY_PREFERRED_FORMAT_FN callback function (winbio_adapter.h)

Article
10/13/2021

Called by the sensor adapter on the biometric unit to determine the input data format preferred by the engine adapter.

Syntax

PIBIO_ENGINE_QUERY_PREFERRED_FORMAT_FN PibioEngineQueryPreferredFormatFn;

HRESULT PibioEngineQueryPreferredFormatFn(
  [in, out] PWINBIO_PIPELINE Pipeline,
  [out]     PWINBIO_REGISTERED_FORMAT StandardFormat,
  [out]     PWINBIO_UUID VendorFormat
)
{...}

Parameters

[in, out] Pipeline

Pointer to a WINBIO_PIPELINE structure associated with the biometric unit performing the operation.

[out] StandardFormat

Pointer to a WINBIO_REGISTERED_FORMAT structure that specifies the format of the data in the StandardDataBlock member of the WINBIO_BIR object. The format is an IBIA-registered name/value pair.

[out] VendorFormat

Pointer to a GUID that receives the vendor-defined format of the data in the VendorDataBlock member of the WINBIO_BIR object.

Return value

If the function succeeds, it returns S_OK. If the function fails, it must return one of the following HRESULT values to indicate the error.

Return code	Description
E_POINTER	A mandatory pointer parameter is NULL.

Remarks

The sensor adapter calls this function to determine the biometric capture format.

Examples

The following pseudocode shows one possible implementation of this function. The example does not compile. You must adapt it to suit your purpose.

//////////////////////////////////////////////////////////////////////////////////////////
//
// EngineAdapterQueryPreferredFormat
//
// Purpose:
//      Called by the sensor adapter on the biometric unit to determine the 
//      input data format preferred by the engine adapter.
//
// Parameters:
//      Pipeline        - Pointer to a WINBIO_PIPELINE structure associated 
//                        with the biometric unit performing the operation.
//      StandardFormat  - Pointer to a WINBIO_REGISTERED_FORMAT structure 
//                        that specifies the format of the data in the 
//                        StandardDataBlock member of the WINBIO_BIR object. 
//                        The format is an IBIA-registered name/value pair.
//      VendorFormat    - Pointer to a GUID that receives the vendor-defined 
//                        format of the data in the VendorDataBlock member of 
//                        the WINBIO_BIR object.
//
static HRESULT
WINAPI
EngineAdapterQueryPreferredFormat(
    __inout PWINBIO_PIPELINE Pipeline,
    __out PWINBIO_REGISTERED_FORMAT StandardFormat,
    __out PWINBIO_UUID VendorFormat
    )
{
   HRESULT hr = S_OK;

   // Verify that pointer arguments are not NULL.
   if (!ARGUMENT_PRESENT(Pipeline) ||
       !ARGUMENT_PRESENT(StandardFormat) ||
       !ARGUMENT_PRESENT(VendorFormat))
   {
        hr = E_POINTER;
        goto cleanup;
   }

   // Specify the preferred data formats.
   StandardFormat->Owner = WINBIO_ANSI_381_FORMAT_OWNER;
   StandardFormat->Type = WINBIO_ANSI_381_FORMAT_TYPE;
   *VendorFormat = VENDOR_UUID_VALUE;

cleanup:

    return hr;
}

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	winbio_adapter.h (include Winbio_adapter.h)