IAMDevMemoryAllocator::GetDevMemoryObject 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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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.]
Syntax
HRESULT GetDevMemoryObject(
[out] IUnknown **ppUnkInnner,
[in] IUnknown *pUnkOuter
);
Parameters
[out] ppUnkInnner
Address of a pointer to the newly created control object's own IUnknown. This inner IUnknown interface should be released when the outer object is destroyed. The custom allocator should call the QueryInterface method on this pointer to obtain the IAMDevMemoryControl interface.
[in] pUnkOuter
Pointer to the custom allocator's own IUnknown interface. This interface aggregates the device memory control object inside the custom allocator.
Return value
Returns an HRESULT value.
Remarks
The device memory control object is necessary to aggregate with the custom allocator, because renderers that require the use of on-board memory will query for IAMDevMemoryControl when they receive a new allocator, to verify that the memory is from the same device. This occurs because the hardware filter will receive an IMemAllocator object, which might or might not use the on-board memory. To decide if it is a compatible allocator, the object would query for the IAMDevMemoryControl interface to access specific methods. The IAMDevMemoryControl creates an aggregated object that implements the methods of IAMDevMemoryControl (these are often hardware-specific).
See COM documentation for rules on how the outer object implements aggregation.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Windows |
| Header | strmif.h (include Dshow.h) |