Microsoft DirectX 8.0 |
The IAMVideoDecimationProperties interface enables an application to control where video decimation occurs. The Overlay Mixer filter implements this interface.
If a video window is smaller than the native size of the video being displayed, the video renderer must decimate the incoming videothat is, scale the video down to the smaller size. Decimation can be performed in one of the following places.
An application can call methods on this interface to select a particular decimation strategy, in order to optimize performance. However, most applications will have no occasion to use this interface. Unless your application is designed to support particular hardware, there is no reason to modify the Overlay Mixer filter's default behavior for decimation.
IUnknown methods Description QueryInterface Retrieves pointers to supported interfaces. AddRef Increments the reference count. Release Decrements the reference count. IAMVideoDecimationProperties methods Description QueryDecimationUsage Retrieves the current decimation strategy. SetDecimationUsage Sets the decimation strategy.
Retrieves the current decimation strategy.
Syntax
HRESULT QueryDecimationUsage( DECIMATION_USAGE *lpUsage );
Parameters
- lpUsage
- [out] Pointer to a variable of type DECIMATION_USAGE that receives the decimation setting.
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_FAIL or another error code otherwise.
Sets the decimation strategy.
Syntax
HRESULT SetDecimationUsage( DECIMATION_USAGE Usage );
Parameters
- Usage
- [in] Member of the DECIMATION_USAGE enumeration that specifies the decimation strategy.
Return Value
Returns an HRESULT value that depends on the implementation of the interface. The DirectShow implementation returns S_OK if successful, or E_INVALIDARG otherwise.