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DXVADDI_VIDEOTRANSFERFUNCTION enumeration (d3dumddi.h)

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The DXVADDI_VIDEOTRANSFERFUNCTION enumeration type contains values that identify the conversion function from R'G'B' to RGB.

Syntax

typedef enum _DXVADDI_VIDEOTRANSFERFUNCTION {
  DXVADDI_VideoTransFuncMask,
  DXVADDI_VideoTransFunc_Unknown,
  DXVADDI_VideoTransFunc_10,
  DXVADDI_VideoTransFunc_18,
  DXVADDI_VideoTransFunc_20,
  DXVADDI_VideoTransFunc_22,
  DXVADDI_VideoTransFunc_709,
  DXVADDI_VideoTransFunc_240M,
  DXVADDI_VideoTransFunc_sRGB,
  DXVADDI_VideoTransFunc_28
} DXVADDI_VIDEOTRANSFERFUNCTION;

Constants

 
DXVADDI_VideoTransFuncMask
Specifies the video transfer function mask. The first 5 (0x001F) bits of a DWORD can be used to specify the video transfer function.
DXVADDI_VideoTransFunc_Unknown
Specifies that the video transfer function is not specified. The default is 22_8bit_sRGB if required for a computation.
DXVADDI_VideoTransFunc_10
Specifies linear RGB conversion (corresponds to gamma = 1.0).
DXVADDI_VideoTransFunc_18
Specifies true 1.8 gamma--that is, L' = pow(L, 1/gamma) for L=0..1.
DXVADDI_VideoTransFunc_20
Specifies true 2.0 gamma--that is, L' = pow(L, 1/gamma) for L=0..1.
DXVADDI_VideoTransFunc_22
Specifies true 2.2 gamma--that is, L' = pow(L, 1/gamma) for L=0..1.

The BT470-2 SysM primaries (that is, the DXVADDI_VIDEOPRIMARIES enumeration type) use gamma 2.2.
DXVADDI_VideoTransFunc_709
Specifies gamma 2.2 curve with a linear range in the low range.

The BT709, SMPTE296M, SMPTE170M, BT470, and SMPTE274M primaries (that is, the DXVADDI_VIDEOPRIMARIES enumeration type) use this video transfer function.
DXVADDI_VideoTransFunc_240M
Specifies gamma 2.2 curve with a linear range in the low range.

The SMPTE240M and interim 274M primaries (that is, the DXVADDI_VIDEOPRIMARIES enumeration type) use this video transfer function.
DXVADDI_VideoTransFunc_sRGB
Specifies gamma 2.4 curve with a linear range in the low range, which makes it match an accurate 2.2 gamma 8-bit curve.
DXVADDI_VideoTransFunc_28
Specifies true 2.8 gamma--that is, L' = pow(L, 1/gamma) for L=0..1.

Remarks

One of the values of DXVADDI_VIDEOTRANSFERFUNCTION can be specified in the VideoTransferFunction member of the DXVADDI_EXTENDEDFORMAT structure.

DXVADDI_VIDEOTRANSFERFUNCTION corresponds to the gamma function of the data. Some transfer functions have corrections to account for 8-bit integer quantization effects.

The following constants can also be used for gamma function:

#define DXVADDI_VideoTransFunc_22_709  DXVADDI_VideoTransFunc_709
#define DXVADDI_VideoTransFunc_22_240M  DXVADDI_VideoTransFunc_240M
#define DXVADDI_VideoTransFunc_22_8bit_sRGB  DXVADDI_VideoTransFunc_sRGB

Requirements

Requirement Value
Minimum supported client Available in Windows Vista and later versions of the Windows operating systems.
Header d3dumddi.h (include D3dumddi.h)

See also

DXVADDI_EXTENDEDFORMAT

DXVADDI_VIDEOPRIMARIES