BdaInitFilter function (bdasup.h)

Article
10/21/2021

The BdaInitFilter function initializes the BDA filter context associated with a filter instance.

Syntax

NTSTATUS BdaInitFilter(
  [in] PKSFILTER                 pKSFilter,
  [in] const BDA_FILTER_TEMPLATE *pBdaFilterTemplate
);

Parameters

[in] pKSFilter

Points to the filter in which to initialize the BDA filter context.

[in] pBdaFilterTemplate

Points to a BDA_FILTER_TEMPLATE structure that describes the filter template for the BDA device. To determine topology for and configure the initialized filter, the network provider uses information referenced in this BDA_FILTER_TEMPLATE structure.

Return value

Returns STATUS_SUCCESS or an appropriate error code.

Remarks

A BDA minidriver calls the BdaInitFilter function to initialize an instance of a filter using a specific BDA filter template and a filter factory that was previously created through a call to the BdaCreateFilterFactory function. The BDA minidriver can subsequently use this filter instance in calls to other BDA support functions, such as, BdaCreatePin.

When a BDA minidriver calls BdaInitFilter, the BDA support driver (Bdasup.sys) creates its own BDA filter context. This BDA filter context is hidden from the BDA minidriver. However, when required, the BDA support driver can access this BDA filter context. The BDA support driver adds a pointer to this BDA filter context to the object bag for the associated KSFILTER object. When the associated KSFILTER object is destroyed, AVStream requests that the BDA support driver delete this BDA filter context from the object bag. In this way, the BDA support driver can destroy this BDA filter context without requiring intervention by the BDA minidriver.

Requirements

Requirement	Value
Minimum supported client	Available on Microsoft Windows XP and later operating systems. This routine is available on the Windows 2000 platform only if Microsoft DirectX 9.0 and later is installed on that platform.
Target Platform	Desktop
Header	bdasup.h (include Bdasup.h)
Library	Bdasup.lib
IRQL	PASSIVE_LEVEL