CTransformFilter.DecideBufferSize method
[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The DecideBufferSize method sets the output pin's buffer requirements.
Syntax
virtual HRESULT DecideBufferSize(
IMemAllocator *pAlloc,
ALLOCATOR_PROPERTIES *ppropInputRequest
) = 0;
Parameters
-
pAlloc
-
Pointer to the IMemAllocator interface on the output pin's allocator.
-
ppropInputRequest
-
Pointer to an ALLOCATOR_PROPERTIES structure that contains buffer requirements from the downstream input pin.
Return value
Returns S_OK or another HRESULT value.
Remarks
The output pin's CTransformOutputPin::DecideBufferSize method calls this method. The derived class must implement this method. For more information, see CBaseOutputPin::DecideBufferSize.
Requirements
| Requirement | Value |
|---|---|
| Header |
|
| Library |
|