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KSMAPPING structure (ks.h)

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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)

See also

KSSTREAM_POINTER_OFFSET

KsDeviceRegisterAdapterObject