Object and Pin Functions

The Wxutil.h and Combase.h header files in the Microsoft® DirectShow® base classes provides helper functions for comparing objects and pins and retrieving interfaces to objects.

EqualPins Checks if two pins are on the same object.

GetInterface Retrieves an interface pointer to the requested client.

IsEqualObject Checks if two interfaces are on the same object.

EqualPins

Checks if two pins are on the same object.

Syntax

BOOL EqualPins(
    IUnknown *pPin1,
    IUnknown *pPin2
);

Parameters

pPin1
Pointer to one pin.
pPin2
Pointer to the other pin.

Return Value

Returns TRUE if both pins are on the same object, or FALSE otherwise.

GetInterface

Object and Pin Functions

Retrieves an interface pointer.

Syntax

HRESULT GetInterface(
    LPUNKNOWN pUnk,
    void **ppv
);

Parameters

pUnk
Pointer to the IUnknown interface.
ppv
Address of a pointer to the retrieved interface.

Return Value

Returns an HRESULT value.

Remarks

This member function performs a thread-safe increment of the reference count. To retrieve the interface and add a reference, call this function from your overriding implementation of the INonDelegatingUnknown::NonDelegatingQueryInterface method.

IsEqualObject

Object and Pin Functions

Checks if two interfaces are on the same object.

Syntax

BOOL WINAPI IsEqualObject(
    IUnknown *pFirst,
    IUnknown *pSecond
);

Parameters

pFirst
Pointer to one interface.
pSecond
Pointer to the other interface.

Return Value

Returns TRUE if the interfaces are both on the same object, or FALSE otherwise.