|Microsoft DirectX 9.0|
The IsVPDecimationAllowed method, given the context, retrieves whether scaling at the video port is possible.
HRESULT IsVPDecimationAllowed( AMVP_CONTEXT amvpContext, LPBOOL pbIsDecimationAllowed );
[in] Context (video or VBI) in which to query the VP decimation capability.
[out] Pointer to the retrieved value indicating whether decimation is allowed.
Returns an HRESULT value.
The Overlay Mixer filter uses this function to determine whether the driver needs the mixer to decimate video data at its own discretion. This function can be especially useful in a capture with preview situation in which you would not want the VP mixer filter to perform any scaling at the video port.