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diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv420.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv420.rst new file mode 100644 index 000000000..f1c7baf32 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv420.rst @@ -0,0 +1,143 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _V4L2-PIX-FMT-YVU420: +.. _V4L2-PIX-FMT-YUV420: + +********************************************************** +V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12') +********************************************************** + + +V4L2_PIX_FMT_YUV420 +Planar formats with ½ horizontal and vertical chroma resolution, also +known as YUV 4:2:0 + + +Description +=========== + +These are planar formats, as opposed to a packed format. The three +components are separated into three sub- images or planes. The Y plane +is first. The Y plane has one byte per pixel. For +``V4L2_PIX_FMT_YVU420``, the Cr plane immediately follows the Y plane in +memory. The Cr plane is half the width and half the height of the Y +plane (and of the image). Each Cr belongs to four pixels, a two-by-two +square of the image. For example, Cr\ :sub:`0` belongs to Y'\ :sub:`00`, +Y'\ :sub:`01`, Y'\ :sub:`10`, and Y'\ :sub:`11`. Following the Cr plane +is the Cb plane, just like the Cr plane. ``V4L2_PIX_FMT_YUV420`` is the +same except the Cb plane comes first, then the Cr plane. + +If the Y plane has pad bytes after each row, then the Cr and Cb planes +have half as many pad bytes after their rows. In other words, two Cx +rows (including padding) is exactly as long as one Y row (including +padding). + +**Byte Order.** +Each cell is one byte. + + + + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + + * - start + 0: + - Y'\ :sub:`00` + - Y'\ :sub:`01` + - Y'\ :sub:`02` + - Y'\ :sub:`03` + * - start + 4: + - Y'\ :sub:`10` + - Y'\ :sub:`11` + - Y'\ :sub:`12` + - Y'\ :sub:`13` + * - start + 8: + - Y'\ :sub:`20` + - Y'\ :sub:`21` + - Y'\ :sub:`22` + - Y'\ :sub:`23` + * - start + 12: + - Y'\ :sub:`30` + - Y'\ :sub:`31` + - Y'\ :sub:`32` + - Y'\ :sub:`33` + * - start + 16: + - Cr\ :sub:`00` + - Cr\ :sub:`01` + * - start + 18: + - Cr\ :sub:`10` + - Cr\ :sub:`11` + * - start + 20: + - Cb\ :sub:`00` + - Cb\ :sub:`01` + * - start + 22: + - Cb\ :sub:`10` + - Cb\ :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 |