KSMAPPING structure (ks.h)
The KSMAPPING structure is used to describe a single contiguous chunk of physical memory for use in scatter/gather DMA operations.
Syntax
typedef struct _KSMAPPING {
PHYSICAL_ADDRESS PhysicalAddress;
ULONG ByteCount;
ULONG Alignment;
} KSMAPPING, *PKSMAPPING;
Members
PhysicalAddress
This member contains the physical address of this piece of the data frame.
ByteCount
This member contains the number of bytes of contiguous physical memory in this individual mapping.
Alignment
This member specifies the memory alignment in bytes for this buffer.
Remarks
In order for minidrivers to use this structure within the stream pointer offsets, the pin for which this is referring must specify scatter/gather DMA mapping generation through KSPIN_FLAG_GENERATE_MAPPINGS and the client must register its DMA adapter object with AVStream using KsDeviceRegisterAdapterObject. See AVStream DMA Services. The KSPIN_FLAG_GENERATE_MAPPINGS flag is defined on the KSPIN_DESCRIPTOR_EX reference page.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Microsoft Windows XP and later operating systems and in Microsoft DirectX 8.0 and later versions. |
| Header | ks.h (include Ks.h) |