Microsoft DirectX 8.0

IAMOverlayFX Interface

The IAMOverlayFX interface is implemented on the Overlay Mixer filter. This interface enables applications to control how the video overlay appears on the user's screen.

Methods in Vtable Order

IUnknown methodsDescription
QueryInterfaceRetrieves pointers to supported interfaces.
AddRefIncrements the reference count.
ReleaseDecrements the reference count.
IAMOverlayFX methodsDescription
QueryOverlayFXCapsRetrieves information about which overlay effects are available to the Overlay Mixer filter.
SetOverlayFXApplies the specified effects to the overlay surface.
GetOverlayFXRetrieves the effects currently applied to the overlay surface, if any.

IAMOverlayFX::GetOverlayFX

IAMOverlayFX Interface

Retrieves the effects currently applied to the overlay surface, if any. The application can call this method while the filter graph is running.

Syntax

HRESULT GetOverlayFX(
    DWORD *lpdwOverlayFX
);

Parameters

lpdwOverlayFX
[out] Pointer a variable that receives a value indicating which effects, if any, are currently applied to the overlay surface. The value is a logical combination of flags from the AMOVERLAYFX enumeration.

Return Value

Returns an HRESULT value that depends on the implementation of the interface. The Microsoft® DirectShow® implementation returns S_OK if successful, or E_POINTER to indicate a NULL pointer argument.

IAMOverlayFX::SetOverlayFX

IAMOverlayFX Interface

Applies the specified effects to the overlay surface.

Syntax

HRESULT SetOverlayFX(
    DWORD dwOverlayFX
);

Parameters

dwOverlayFX
[in] Value specifying which effects to apply. The value must be a logical combination of flags from the AMOVERLAYFX enumeration, or the method returns E_INVALIDARG.

Return Value

Returns an HRESULT value that depends on the implementation of the interface. The DirectShow implementation may return one of the following values, or others not listed.

E_FAILFailure.
E_INVALIDARGInvalid argument.
S_OKSuccess.

Remarks

The application must call this method while the filter graph is running. The effects are applied immediately.

IAMOverlayFX::QueryOverlayFXCaps

IAMOverlayFX Interface

Retrieves information about which overlay effects are available to the Overlay Mixer filter.

Syntax

HRESULT QueryOverlayFXCaps(
    DWORD *lpdwOverlayFXCaps
);

Parameters

lpdwOverlayFXCaps
[out] Pointer to a variable that receives a value indicating the overlay effects capabilities of the overlay surface. The value is a logical combination of flags from the AMOVERLAYFX enumeration.

Return Value

Returns an HRESULT value that depends on the implementation of the interface. The DirectShow implementation returns one of the following values.

E_FAILFailure.
E_POINTERNull pointer argument.
S_OKSuccess.