GetAllocator method retrieves the memory allocator proposed by this pin. This method implements the IMemInputPin::GetAllocator method.
Address of a variable that receives a pointer to the allocator's IMemAllocator interface.
Returns S_OK if successful, or an error code from the CoCreateInstance function.
This method creates a CMemAllocator object. Override this method if your filter uses an allocator from a downstream pin, or a custom allocator.
If the method succeeds, the IMemAllocator interface has an outstanding reference count. Be sure to release it when you are done.