IMediaTransform::QueryBufferRequirements method
Windows Movie Maker calls the QueryBufferRequirements method on startup to learn any special buffer requirements of the transform.
Syntax
HRESULT QueryBufferRequirements(
[in] DWORD dwStream,
[out] BufferFormat *pFormat
);
Parameters
-
dwStream [in]
-
One of the following DWORD values specifying an input or output stream:
0 indicates the output stream.
1 indicates the first input stream.
2 indicates the second input stream.
The transform should indicate the total number of input streams in its implementation of get_InputCount.
-
pFormat [out]
-
Pointer to a BufferFormat structure that specifies the format for that stream. The caller allocates this structure; the transform should fill it with the buffer requirements. For more information, see Remarks.
Return value
The method returns an HRESULT of S_OK for success, or a standard COM error code for failure.
Remarks
Most transforms will not have any special buffer requirements; unless your transform has special requirements, this method should return S_OK and not process the pFormat parameter that is passed in.
Requirements
| Minimum supported client |
Windows Vista [desktop apps only] |
| Minimum supported server |
Windows Server 2008 [desktop apps only] |
| Header |
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| Library |
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