2.7.1.2. Planar YUV formats

Planar formats split luma and chroma data in separate memory regions. They exist in two variants:

  • Semi-planar formats use two planes. The first plane is the luma plane and stores the Y components. The second plane is the chroma plane and stores the Cb and Cr components interleaved.

  • Fully planar formats use three planes to store the Y, Cb and Cr components separately.

Within a plane, components are stored in pixel order, which may be linear or tiled. Padding may be supported at the end of the lines, and the line stride of the chroma planes may be constrained by the line stride of the luma plane.

Some planar formats allow planes to be placed in independent memory locations. They are identified by an ‘M’ suffix in their name (such as in V4L2_PIX_FMT_NV12M). Those formats are intended to be used only in drivers and applications that support the multi-planar API, described in Single- and multi-planar APIs. Unless explicitly documented as supporting non-contiguous planes, formats require the planes to follow each other immediately in memory.

2.7.1.2.1. Semi-Planar YUV Formats

These formats are commonly referred to as NV formats (NV12, NV16, …). They use two planes, and store the luma components in the first plane and the chroma components in the second plane. The Cb and Cr components are interleaved in the chroma plane, with Cb and Cr always stored in pairs. The chroma order is exposed as different formats.

For memory contiguous formats, the number of padding pixels at the end of the chroma lines is identical to the padding of the luma lines. Without horizontal subsampling, the chroma line stride (in bytes) is thus equal to twice the luma line stride. With horizontal subsampling by 2, the chroma line stride is equal to the luma line stride. Vertical subsampling doesn’t affect the line stride.

For non-contiguous formats, no constraints are enforced by the format on the relationship between the luma and chroma line padding and stride.

All components are stored with the same number of bits per component.

Overview of Semi-Planar YUV Formats

Identifier

Code

Bits per component

Subsampling

Chroma order 1

Contiguous 2

Tiling 3

V4L2_PIX_FMT_NV12

‘NV12’

8

4:2:0

Cb, Cr

Yes

Linear

V4L2_PIX_FMT_NV21

‘NV21’

8

4:2:0

Cr, Cb

Yes

Linear

V4L2_PIX_FMT_NV12M

‘NM12’

8

4:2:0

Cb, Cr

No

Linear

V4L2_PIX_FMT_NV21M

‘NM21’

8

4:2:0

Cr, Cb

No

Linear

V4L2_PIX_FMT_NV12MT

‘TM12’

8

4:2:0

Cb, Cr

No

64x32 tiles

Horizontal Z order

V4L2_PIX_FMT_NV12MT_16X16

‘VM12’

8

4:2:2

Cb, Cr

No

16x16 tiles

V4L2_PIX_FMT_P010

‘P010’

10

4:2:0

Cb, Cr

Yes

Linear

V4L2_PIX_FMT_NV16

‘NV16’

8

4:2:2

Cb, Cr

Yes

Linear

V4L2_PIX_FMT_NV61

‘NV61’

8

4:2:2

Cr, Cb

Yes

Linear

V4L2_PIX_FMT_NV16M

‘NM16’

8

4:2:2

Cb, Cr

No

Linear

V4L2_PIX_FMT_NV61M

‘NM61’

8

4:2:2

Cr, Cb

No

Linear

V4L2_PIX_FMT_NV24

‘NV24’

8

4:4:4

Cb, Cr

Yes

Linear

V4L2_PIX_FMT_NV42

‘NV42’

8

4:4:4

Cr, Cb

Yes

Linear

1

Order of chroma samples in the second plane

2

Indicates if planes have to be contiguous in memory or can be disjoint

3

Macroblock size in pixels

Color Sample Location: Chroma samples are interstitially sited horizontally.

2.7.1.2.1.1. NV12, NV21, NV12M and NV21M

Semi-planar YUV 4:2:0 formats. The chroma plane is subsampled by 2 in each direction. Chroma lines contain half the number of pixels and the same number of bytes as luma lines, and the chroma plane contains half the number of lines of the luma plane.

Sample 4x4 NV12 Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 4:

Y’10

Y’11

Y’12

Y’13

start + 8:

Y’20

Y’21

Y’22

Y’23

start + 12:

Y’30

Y’31

Y’32

Y’33

start + 16:

Cb00

Cr00

Cb01

Cr01

start + 20:

Cb10

Cr10

Cb11

Cr11

Sample 4x4 NV12M Image

start0 + 0:

Y’00

Y’01

Y’02

Y’03

start0 + 4:

Y’10

Y’11

Y’12

Y’13

start0 + 8:

Y’20

Y’21

Y’22

Y’23

start0 + 12:

Y’30

Y’31

Y’32

Y’33

start1 + 0:

Cb00

Cr00

Cb01

Cr01

start1 + 4:

Cb10

Cr10

Cb11

Cr11

2.7.1.2.1.2. Tiled NV12

Semi-planar YUV 4:2:0 formats, using macroblock tiling. The chroma plane is subsampled by 2 in each direction. Chroma lines contain half the number of pixels and the same number of bytes as luma lines, and the chroma plane contains half the number of lines of the luma plane. Each tile follows the previous one linearly in memory (from left to right, top to bottom).

V4L2_PIX_FMT_NV12MT_16X16 is similar to V4L2_PIX_FMT_NV12M but stores pixels in 2D 16x16 tiles, and stores tiles linearly in memory. The line stride and image height must be aligned to a multiple of 16. The layouts of the luma and chroma planes are identical.

V4L2_PIX_FMT_NV12MT is similar to V4L2_PIX_FMT_NV12M but stores pixels in 2D 64x32 tiles, and stores 2x2 groups of tiles in Z-order in memory, alternating Z and mirrored Z shapes horizontally. The line stride must be a multiple of 128 pixels to ensure an integer number of Z shapes. The image height must be a multiple of 32 pixels. If the vertical resolution is an odd number of tiles, the last row of tiles is stored in linear order. The layouts of the luma and chroma planes are identical.

V4L2_PIX_FMT_NV12_4L4 stores pixels in 4x4 tiles, and stores tiles linearly in memory. The line stride and image height must be aligned to a multiple of 4. The layouts of the luma and chroma planes are identical.

V4L2_PIX_FMT_NV12_16L16 stores pixels in 16x16 tiles, and stores tiles linearly in memory. The line stride and image height must be aligned to a multiple of 16. The layouts of the luma and chroma planes are identical.

V4L2_PIX_FMT_NV12_32L32 stores pixels in 32x32 tiles, and stores tiles linearly in memory. The line stride and image height must be aligned to a multiple of 32. The layouts of the luma and chroma planes are identical.

V4L2_PIX_FMT_NV12M_8L128 is similar to V4L2_PIX_FMT_NV12M but stores pixels in 2D 8x128 tiles, and stores tiles linearly in memory. The image height must be aligned to a multiple of 128. The layouts of the luma and chroma planes are identical.

V4L2_PIX_FMT_NV12M_10BE_8L128 is similar to V4L2_PIX_FMT_NV12M but stores 10 bits pixels in 2D 8x128 tiles, and stores tiles linearly in memory. the data is arranged in big endian order. The image height must be aligned to a multiple of 128. The layouts of the luma and chroma planes are identical. Note the tile size is 8bytes multiplied by 128 bytes, it means that the low bits and high bits of one pixel may be in different tiles. The 10 bit pixels are packed, so 5 bytes contain 4 10-bit pixels layout like this (for luma): byte 0: Y0(bits 9-2) byte 1: Y0(bits 1-0) Y1(bits 9-4) byte 2: Y1(bits 3-0) Y2(bits 9-6) byte 3: Y2(bits 5-0) Y3(bits 9-8) byte 4: Y3(bits 7-0)

V4L2_PIX_FMT_MM21 store luma pixel in 16x32 tiles, and chroma pixels in 16x16 tiles. The line stride must be aligned to a multiple of 16 and the image height must be aligned to a multiple of 32. The number of luma and chroma tiles are identical, even though the tile size differ. The image is formed of two non-contiguous planes.

nv12mt.svg

V4L2_PIX_FMT_NV12MT macroblock Z shape memory layout

nv12mt_example.svg

Example V4L2_PIX_FMT_NV12MT memory layout of tiles

2.7.1.2.1.3. NV16, NV61, NV16M and NV61M

Semi-planar YUV 4:2:2 formats. The chroma plane is subsampled by 2 in the horizontal direction. Chroma lines contain half the number of pixels and the same number of bytes as luma lines, and the chroma plane contains the same number of lines as the luma plane.

Sample 4x4 NV16 Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 4:

Y’10

Y’11

Y’12

Y’13

start + 8:

Y’20

Y’21

Y’22

Y’23

start + 12:

Y’30

Y’31

Y’32

Y’33

start + 16:

Cb00

Cr00

Cb01

Cr01

start + 20:

Cb10

Cr10

Cb11

Cr11

start + 24:

Cb20

Cr20

Cb21

Cr21

start + 28:

Cb30

Cr30

Cb31

Cr31

Sample 4x4 NV16M Image

start0 + 0:

Y’00

Y’01

Y’02

Y’03

start0 + 4:

Y’10

Y’11

Y’12

Y’13

start0 + 8:

Y’20

Y’21

Y’22

Y’23

start0 + 12:

Y’30

Y’31

Y’32

Y’33

start1 + 0:

Cb00

Cr00

Cb02

Cr02

start1 + 4:

Cb10

Cr10

Cb12

Cr12

start1 + 8:

Cb20

Cr20

Cb22

Cr22

start1 + 12:

Cb30

Cr30

Cb32

Cr32

2.7.1.2.1.4. NV24 and NV42

Semi-planar YUV 4:4:4 formats. The chroma plane is not subsampled. Chroma lines contain the same number of pixels and twice the number of bytes as luma lines, and the chroma plane contains the same number of lines as the luma plane.

Sample 4x4 NV24 Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 4:

Y’10

Y’11

Y’12

Y’13

start + 8:

Y’20

Y’21

Y’22

Y’23

start + 12:

Y’30

Y’31

Y’32

Y’33

start + 16:

Cb00

Cr00

Cb01

Cr01

Cb02

Cr02

Cb03

Cr03

start + 24:

Cb10

Cr10

Cb11

Cr11

Cb12

Cr12

Cb13

Cr13

start + 32:

Cb20

Cr20

Cb21

Cr21

Cb22

Cr22

Cb23

Cr23

start + 40:

Cb30

Cr30

Cb31

Cr31

Cb32

Cr32

Cb33

Cr33

2.7.1.2.1.5. P010

Like NV12 with 10 bits per component, expanded to 16 bits. Data in the 10 high bits, zeros in the 6 low bits, arranged in little endian order.

Sample 4x4 P010 Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 8:

Y’10

Y’11

Y’12

Y’13

start + 16:

Y’20

Y’21

Y’22

Y’23

start + 24:

Y’30

Y’31

Y’32

Y’33

start + 32:

Cb00

Cr00

Cb01

Cr01

start + 40:

Cb10

Cr10

Cb11

Cr11

2.7.1.2.2. Fully Planar YUV Formats

These formats store the Y, Cb and Cr components in three separate planes. The luma plane comes first, and the order of the two chroma planes varies between formats. The two chroma planes always use the same subsampling.

For memory contiguous formats, the number of padding pixels at the end of the chroma lines is identical to the padding of the luma lines. The chroma line stride (in bytes) is thus equal to the luma line stride divided by the horizontal subsampling factor. Vertical subsampling doesn’t affect the line stride.

For non-contiguous formats, no constraints are enforced by the format on the relationship between the luma and chroma line padding and stride.

All components are stored with the same number of bits per component.

Overview of Fully Planar YUV Formats

Identifier

Code

Bits per component

Subsampling

Planes order 4

Contiguous 5

V4L2_PIX_FMT_YUV410

‘YUV9’

8

4:1:0

Y, Cb, Cr

Yes

V4L2_PIX_FMT_YVU410

‘YVU9’

8

4:1:0

Y, Cr, Cb

Yes

V4L2_PIX_FMT_YUV411P

‘411P’

8

4:1:1

Y, Cb, Cr

Yes

V4L2_PIX_FMT_YUV420M

‘YM12’

8

4:2:0

Y, Cb, Cr

No

V4L2_PIX_FMT_YVU420M

‘YM21’

8

4:2:0

Y, Cr, Cb

No

V4L2_PIX_FMT_YUV420

‘YU12’

8

4:2:0

Y, Cb, Cr

Yes

V4L2_PIX_FMT_YVU420

‘YV12’

8

4:2:0

Y, Cr, Cb

Yes

V4L2_PIX_FMT_YUV422P

‘422P’

8

4:2:2

Y, Cb, Cr

Yes

V4L2_PIX_FMT_YUV422M

‘YM16’

8

4:2:2

Y, Cb, Cr

No

V4L2_PIX_FMT_YVU422M

‘YM61’

8

4:2:2

Y, Cr, Cb

No

V4L2_PIX_FMT_YUV444M

‘YM24’

8

4:4:4

Y, Cb, Cr

No

V4L2_PIX_FMT_YVU444M

‘YM42’

8

4:4:4

Y, Cr, Cb

No

4

Order of luma and chroma planes

5

Indicates if planes have to be contiguous in memory or can be disjoint

Color Sample Location: Chroma samples are interstitially sited horizontally.

2.7.1.2.2.1. YUV410 and YVU410

Planar YUV 4:1:0 formats. The chroma planes are subsampled by 4 in each direction. Chroma lines contain a quarter of the number of pixels and bytes of the luma lines, and the chroma planes contain a quarter of the number of lines of the luma plane.

Sample 4x4 YUV410 Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 4:

Y’10

Y’11

Y’12

Y’13

start + 8:

Y’20

Y’21

Y’22

Y’23

start + 12:

Y’30

Y’31

Y’32

Y’33

start + 16:

Cr00

start + 17:

Cb00

2.7.1.2.2.2. YUV411P

Planar YUV 4:1:1 formats. The chroma planes are subsampled by 4 in the horizontal direction. Chroma lines contain a quarter of the number of pixels and bytes of the luma lines, and the chroma planes contain the same number of lines as the luma plane.

Sample 4x4 YUV411P Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 4:

Y’10

Y’11

Y’12

Y’13

start + 8:

Y’20

Y’21

Y’22

Y’23

start + 12:

Y’30

Y’31

Y’32

Y’33

start + 16:

Cb00

start + 17:

Cb10

start + 18:

Cb20

start + 19:

Cb30

start + 20:

Cr00

start + 21:

Cr10

start + 22:

Cr20

start + 23:

Cr30

2.7.1.2.2.3. YUV420, YVU420, YUV420M and YVU420M

Planar YUV 4:2:0 formats. The chroma planes are subsampled by 2 in each direction. Chroma lines contain half of the number of pixels and bytes of the luma lines, and the chroma planes contain half of the number of lines of the luma plane.

Sample 4x4 YUV420 Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 4:

Y’10

Y’11

Y’12

Y’13

start + 8:

Y’20

Y’21

Y’22

Y’23

start + 12:

Y’30

Y’31

Y’32

Y’33

start + 16:

Cr00

Cr01

start + 18:

Cr10

Cr11

start + 20:

Cb00

Cb01

start + 22:

Cb10

Cb11

Sample 4x4 YUV420M Image

start0 + 0:

Y’00

Y’01

Y’02

Y’03

start0 + 4:

Y’10

Y’11

Y’12

Y’13

start0 + 8:

Y’20

Y’21

Y’22

Y’23

start0 + 12:

Y’30

Y’31

Y’32

Y’33

start1 + 0:

Cb00

Cb01

start1 + 2:

Cb10

Cb11

start2 + 0:

Cr00

Cr01

start2 + 2:

Cr10

Cr11

2.7.1.2.2.4. YUV422P, YUV422M and YVU422M

Planar YUV 4:2:2 formats. The chroma planes are subsampled by 2 in the horizontal direction. Chroma lines contain half of the number of pixels and bytes of the luma lines, and the chroma planes contain the same number of lines as the luma plane.

Sample 4x4 YUV422P Image

start + 0:

Y’00

Y’01

Y’02

Y’03

start + 4:

Y’10

Y’11

Y’12

Y’13

start + 8:

Y’20

Y’21

Y’22

Y’23

start + 12:

Y’30

Y’31

Y’32

Y’33

start + 16:

Cb00

Cb01

start + 18:

Cb10

Cb11

start + 20:

Cb20

Cb21

start + 22:

Cb30

Cb31

start + 24:

Cr00

Cr01

start + 26:

Cr10

Cr11

start + 28:

Cr20

Cr21

start + 30:

Cr30

Cr31

Sample 4x4 YUV422M Image

start0 + 0:

Y’00

Y’01

Y’02

Y’03

start0 + 4:

Y’10

Y’11

Y’12

Y’13

start0 + 8:

Y’20

Y’21

Y’22

Y’23

start0 + 12:

Y’30

Y’31

Y’32

Y’33

start1 + 0:

Cb00

Cb01

start1 + 2:

Cb10

Cb11

start1 + 4:

Cb20

Cb21

start1 + 6:

Cb30

Cb31

start2 + 0:

Cr00

Cr01

start2 + 2:

Cr10

Cr11

start2 + 4:

Cr20

Cr21

start2 + 6:

Cr30

Cr31

2.7.1.2.2.5. YUV444M and YVU444M

Planar YUV 4:4:4 formats. The chroma planes are no subsampled. Chroma lines contain the same number of pixels and bytes of the luma lines, and the chroma planes contain the same number of lines as the luma plane.

Sample 4x4 YUV444M Image

start0 + 0:

Y’00

Y’01

Y’02

Y’03

start0 + 4:

Y’10

Y’11

Y’12

Y’13

start0 + 8:

Y’20

Y’21

Y’22

Y’23

start0 + 12:

Y’30

Y’31

Y’32

Y’33

start1 + 0:

Cb00

Cb01

Cb02

Cb03

start1 + 4:

Cb10

Cb11

Cb12

Cb13

start1 + 8:

Cb20

Cb21

Cb22

Cb23

start1 + 12:

Cb20

Cb21

Cb32

Cb33

start2 + 0:

Cr00

Cr01

Cr02

Cr03

start2 + 4:

Cr10

Cr11

Cr12

Cr13

start2 + 8:

Cr20

Cr21

Cr22

Cr23

start2 + 12:

Cr30

Cr31

Cr32

Cr33