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diff --git a/Documentation/userspace-api/media/v4l/pixfmt-nv12m.rst b/Documentation/userspace-api/media/v4l/pixfmt-nv12m.rst new file mode 100644 index 000000000000..115ea603c13f --- /dev/null +++ b/Documentation/userspace-api/media/v4l/pixfmt-nv12m.rst @@ -0,0 +1,151 @@ +.. Permission is granted to copy, distribute and/or modify this +.. document under the terms of the GNU Free Documentation License, +.. Version 1.1 or any later version published by the Free Software +.. Foundation, with no Invariant Sections, no Front-Cover Texts +.. and no Back-Cover Texts. A copy of the license is included at +.. Documentation/userspace-api/media/fdl-appendix.rst. +.. +.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections + +.. _V4L2-PIX-FMT-NV12M: +.. _v4l2-pix-fmt-nv12mt-16x16: +.. _V4L2-PIX-FMT-NV21M: + +*********************************************************************************** +V4L2_PIX_FMT_NV12M ('NM12'), V4L2_PIX_FMT_NV21M ('NM21'), V4L2_PIX_FMT_NV12MT_16X16 +*********************************************************************************** + + +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. + + +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, Cb\ :sub:`0`/Cr\ :sub:`0` belongs to +Y'\ :sub:`00`, Y'\ :sub:`01`, Y'\ :sub:`10`, Y'\ :sub:`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 +:ref:`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. + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + + * - start0 + 0: + - Y'\ :sub:`00` + - Y'\ :sub:`01` + - Y'\ :sub:`02` + - Y'\ :sub:`03` + * - start0 + 4: + - Y'\ :sub:`10` + - Y'\ :sub:`11` + - Y'\ :sub:`12` + - Y'\ :sub:`13` + * - start0 + 8: + - Y'\ :sub:`20` + - Y'\ :sub:`21` + - Y'\ :sub:`22` + - Y'\ :sub:`23` + * - start0 + 12: + - Y'\ :sub:`30` + - Y'\ :sub:`31` + - Y'\ :sub:`32` + - Y'\ :sub:`33` + * - + * - start1 + 0: + - Cb\ :sub:`00` + - Cr\ :sub:`00` + - Cb\ :sub:`01` + - Cr\ :sub:`01` + * - start1 + 4: + - Cb\ :sub:`10` + - Cr\ :sub:`10` + - Cb\ :sub:`11` + - Cr\ :sub:`11` + + +**Color Sample Location:** + + + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + + * - + - 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 |