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4/8/2010

This method retrieves the optimizations required to process the next sample, given the optimizations already agreed to by the application.

Syntax

HRESULT GetCurrentSampleRequirements(
  ULONG 
ulOutputStreamIndex,
  DWORD* 
pdwRequestedFeatures
);

Parameters

ulOutputStreamIndex

Zero-based index of an output stream on the DMO.

pdwRequestedFeatures

Pointer to a variable that receives the required optimizations. The returned value is a bitwise combination of zero or more flags from the DMO_VIDEO_OUTPUT_STREAM_FLAGSenumeration.

Return Value

Returns an HRESULTvalue. Possible values include the following.

Value Description

S_OK

Success

DMO_E_INVALIDSTREAMINDEX

Invalid stream index

E_POINTER

NULL pointer argument

Remarks

After an application calls the IDMOVideoOutputOptimizations::SetOperationModemethod, it must provide all the optimizations it has agreed to. However, the DMO might not require every optimization on every sample. This method enables the DMO to waive an agreed-on optimization for one sample.

Before processing a sample, the application can call this method. If the DMO does not require an optimization to process the next sample, it omits the corresponding flag from the pdwRequestedFeaturesparameter. For the next sample only, the application can ignore the optimization. The results of this method are valid only for the next call to the IMediaObject::ProcessOutputmethod.

The DMO will return only the flags that were agreed to in the SetOperationModemethod. In other words, you cannot dynamically enable new optimizations with this method.

Requirements

Header dmo.h
Library Dmoguid.lib
Windows Embedded CE Windows CE .NET 4.1 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also