Description

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 the section called “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.