IMemInputPin::GetAllocator method (strmif.h)
[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 GetAllocator method retrieves the memory allocator proposed by this pin. After the allocator has been selected, this method returns a pointer to the selected allocator.
Syntax
HRESULT GetAllocator(
[out] IMemAllocator **ppAllocator
);
Parameters
[out] ppAllocator
Receives a pointer to the allocator's IMemAllocator interface. The caller must release the interface.
Return value
Returns an HRESULT value. Possible values include those shown in the following table.
| Return code | Description |
|---|---|
|
Success. |
|
No allocator is available. |
Remarks
When an output pin connects to an input pin, it negotiates with the input pin to decide on a memory allocator. The output pin calls this method to retrieve the input pin's proposed allocator. It calls the IMemInputPin::NotifyAllocator method to specify which allocator it selected.
If this method succeeds, the IMemAllocator interface has an outstanding reference count. Be sure to release it when you are done.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | strmif.h (include Dshow.h) |
| Library | Strmiids.lib |