V4L2_PIX_FMT_NV21M V4L2_PIX_FMT_NV12MT_16X16 Variation of V4L2_PIX_FMT_NV12 and V4L2_PIX_FMT_NV21 with planes non contiguous in memory.
This is a multi-planar, two-plane version of the YUV 4:2:0 format. The three components are separated into two sub-images or planes. V4L2_PIX_FMT_NV12M differs from V4L2_PIX_FMT_NV12 in that the two planes are non-contiguous in memory, i.e. the chroma plane do not necessarily immediately follows the luma plane. The luminance data occupies the first plane. The Y plane has one byte per pixel. In the second plane there is a chrominance data with alternating chroma samples. The CbCr plane is the same width, in bytes, as the Y plane (and of the image), but is half as tall in pixels. Each CbCr pair belongs to four pixels. For example, Cb0/Cr0 belongs to Y’00, Y’01, Y’10, Y’11. V4L2_PIX_FMT_NV12MT_16X16 is the tiled version of V4L2_PIX_FMT_NV12M with 16x16 macroblock tiles. Here pixels are arranged in 16x16 2D tiles and tiles are arranged in linear order in memory. V4L2_PIX_FMT_NV21M is the same as V4L2_PIX_FMT_NV12M except the Cb and Cr bytes are swapped, the CrCb plane starts with a Cr byte.
V4L2_PIX_FMT_NV12M is intended to be used only in drivers and applications that support the multi-planar API, described in Single- and multi-planar APIs.
If the Y plane has pad bytes after each row, then the CbCr plane has as many pad bytes after its rows.
Byte Order. Each cell is one byte.
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 |
Color Sample Location..
0 | 1 | 2 | 3 | ||||
0 | Y | Y | Y | Y | |||
C | C | ||||||
1 | Y | Y | Y | Y | |||
2 | Y | Y | Y | Y | |||
C | C | ||||||
3 | Y | Y | Y | Y |