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DXVA2_DecodeBufferDesc structure (dxva2api.h)

  • Article

Describes a buffer sent from a decoder to a DirectX Video Acceleration (DXVA) device.

Syntax

typedef struct _DXVA2_DecodeBufferDesc {
  DWORD CompressedBufferType;
  UINT  BufferIndex;
  UINT  DataOffset;
  UINT  DataSize;
  UINT  FirstMBaddress;
  UINT  NumMBsInBuffer;
  UINT  Width;
  UINT  Height;
  UINT  Stride;
  UINT  ReservedBits;
  PVOID pvPVPState;
} DXVA2_DecodeBufferDesc;

Members

CompressedBufferType

Identifies the type of buffer passed to the accelerator. Must be one of the following values.

Value Meaning
DXVA2_PictureParametersBufferType
 Picture decoding parameter buffer.
DXVA2_MacroBlockControlBufferType
 Macroblock control command buffer.
DXVA2_ResidualDifferenceBufferType
 Residual difference block data buffer.
DXVA2_DeblockingControlBufferType
 Deblocking filter control command buffer.
DXVA2_InverseQuantizationMatrixBufferType
 Inverse quantization matrix buffer.
DXVA2_SliceControlBufferType
 Slice-control buffer.
DXVA2_BitStreamDateBufferType
 Bitstream data buffer.
DXVA2_MotionVectorBuffer
 Motion vector buffer.
DXVA2_FilmGrainBuffer
 Film grain synthesis data buffer.

BufferIndex

Reserved. Set to zero.

DataOffset

Specifies the offset of the relevant data from the beginning of the buffer, in bytes. Currently this value must be zero.

DataSize

Specifies the amount of relevant data in the buffer, in bytes. The location of the last byte of content in the buffer is DataOffset + DataSize − 1.

FirstMBaddress

Specifies the macroblock address of the first macroblock in the buffer. The macroblock address is given in raster scan order.

NumMBsInBuffer

Specifies the number of macroblocks of data in the buffer. This count includes skipped macroblocks. This value must be zero if the data buffer type is one of the following: picture decoding parameters, inverse-quantization matrix, AYUV, IA44/AI44, DPXD, Highlight, or DCCMD.

Width

Reserved. Set to zero.

Height

Reserved. Set to zero.

Stride

Reserved. Set to zero.

ReservedBits

Reserved. Set to zero.

pvPVPState

Pointer to a byte array that contains an initialization vector (IV) for encrypted data. If the decode buffer does not contain encrypted data, set this member to NULL. If the decode buffer contains encrypted data, the contents of pvPVPState depends on the type of encryption. For D3DCRYPTOTYPE_AES128_CTR, the pvPVPState member points to a DXVA2_AES_CTR_IV structure.

Remarks

This structure corresponds closely to the DXVA_BufferDescription structure in DXVA 1, but some of the fields are no longer used in DXVA 2.

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Header dxva2api.h

See also

DirectX Video Acceleration 2.0

Media Foundation Structures