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DXVA2_VideoChromaSubSampling enumeration (dxva2api.h)
Describes how chroma values are positioned relative to the luma samples in a YUV video frame. These flags are used in the DXVA2_ExtendedFormat structure.
Syntax
typedef enum _DXVA2_VideoChromaSubSampling {
DXVA2_VideoChromaSubsamplingMask = 0xf,
DXVA2_VideoChromaSubsampling_Unknown = 0,
DXVA2_VideoChromaSubsampling_ProgressiveChroma = 0x8,
DXVA2_VideoChromaSubsampling_Horizontally_Cosited = 0x4,
DXVA2_VideoChromaSubsampling_Vertically_Cosited = 0x2,
DXVA2_VideoChromaSubsampling_Vertically_AlignedChromaPlanes = 0x1,
DXVA2_VideoChromaSubsampling_MPEG2,
DXVA2_VideoChromaSubsampling_MPEG1,
DXVA2_VideoChromaSubsampling_DV_PAL,
DXVA2_VideoChromaSubsampling_Cosited
} DXVA2_VideoChromaSubSampling;
Constants
DXVA2_VideoChromaSubsamplingMaskValue: 0xf Bitmask to validate flag values. This value is not a valid flag. |
DXVA2_VideoChromaSubsampling_UnknownValue: 0 Unknown encoding scheme. |
DXVA2_VideoChromaSubsampling_ProgressiveChromaValue: 0x8 Chroma should be reconstructed as if the underlying video was progressive content, rather than skipping fields or applying chroma filtering to minimize artifacts from reconstructing 4:2:0 interlaced chroma. |
DXVA2_VideoChromaSubsampling_Horizontally_CositedValue: 0x4 Horizontally cosited. Chroma samples are aligned horizontally with multiples of the luma samples. If this flag is not set, chroma samples are located 1/2 pixel to the right of the corresponding luma samples. |
DXVA2_VideoChromaSubsampling_Vertically_CositedValue: 0x2 Vertically cosited. Chroma samples are aligned vertically with multiples of the luma samples. If this flag is not set, chroma samples are located 1/2 pixel down from the corresponding luma samples. |
DXVA2_VideoChromaSubsampling_Vertically_AlignedChromaPlanesValue: 0x1 The chroma planes are vertically aligned. If this flag is not set, chroma planes are out of phase by 1/2 chroma sample, and the Cb and Cr samples are sited on alternate lines. |
DXVA2_VideoChromaSubsampling_MPEG2Specifies the chroma encoding scheme for MPEG-2 video. Chroma samples are aligned horizontally with the luma samples, but are not aligned vertically. The U and V planes are aligned vertically. |
DXVA2_VideoChromaSubsampling_MPEG1Specifies the chroma encoding scheme for MPEG-1 video. |
DXVA2_VideoChromaSubsampling_DV_PALSpecifies the chroma encoding scheme for PAL DV video. |
DXVA2_VideoChromaSubsampling_CositedHorizontally and vertically cosited. Chroma samples are aligned vertically and horizontally with the luma samples. YUV formats such as 4:4:4, 4:2:2, and 4:1:1 are always cosited in both directions and should use this flag. |
Remarks
The following diagrams show the most common arrangements.
4:4:4 horizontally and vertically cosited.
👁 Diagram showing 4x4 grid; each cell contains two circles--one for luma and one for chroma
4:2:2 horizontally and vertically cosited.
👁 Diagram similar to the original one, but cells in the second and fourth columns have luma but not chroma
4:1:1 horizontally and vertically cosited.
👁 Diagram similar to the original one, but only cells in the first column contain chroma
4:2:0 progressive, horizontally cosited.
👁 Diagram similar to the original one, but chroma circles appear only on odd-numbered row boundaries in odd-numbered columns
Example: MPEG-2 progressive.
4:2:0 progressive, not cosited horizontally or vertically.
👁 Diagram similar to the original one, but chroma circles appear only at intersections of odd-numbered row boundaries and odd-numbered columns boundaries
Example: JPEG progressive.
4:2:0 interlaced, vertically cosited; chroma planes out of phase.
👁 Diagram showing two 4x4 matrices; one is lower than the other by half the width of a row, and chroma circles in each column alternate between Cr and Cb
Example: DV PAL interlaced.
4:2:0 interlaced, horizontally cosited.
👁 Diagram showing two instances of the fourth diagram; one is lower than the other by half the width of a row
Example: MPEG-2 interlaced.
This enumeration is equivalent to the DXVA_VideoChromaSubsampling enumeration used in DXVA 1.0.
If you are using the IMFMediaType interface to describe the video format, chroma siting is specified in the MF_MT_VIDEO_CHROMA_SITING attribute.
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
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