1.. Permission is granted to copy, distribute and/or modify this 2.. document under the terms of the GNU Free Documentation License, 3.. Version 1.1 or any later version published by the Free Software 4.. Foundation, with no Invariant Sections, no Front-Cover Texts 5.. and no Back-Cover Texts. A copy of the license is included at 6.. Documentation/media/uapi/fdl-appendix.rst. 7.. 8.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections 9 10.. _V4L2-PIX-FMT-YUV420M: 11.. _v4l2-pix-fmt-yvu420m: 12 13************************************************************ 14V4L2_PIX_FMT_YUV420M ('YM12'), V4L2_PIX_FMT_YVU420M ('YM21') 15************************************************************ 16 17 18V4L2_PIX_FMT_YVU420M 19Variation of ``V4L2_PIX_FMT_YUV420`` and ``V4L2_PIX_FMT_YVU420`` with 20planes non contiguous in memory. 21 22 23Description 24=========== 25 26This is a multi-planar format, as opposed to a packed format. The three 27components are separated into three sub-images or planes. 28 29The Y plane is first. The Y plane has one byte per pixel. For 30``V4L2_PIX_FMT_YUV420M`` the Cb data constitutes the second plane which 31is half the width and half the height of the Y plane (and of the image). 32Each Cb belongs to four pixels, a two-by-two square of the image. For 33example, Cb\ :sub:`0` belongs to Y'\ :sub:`00`, Y'\ :sub:`01`, 34Y'\ :sub:`10`, and Y'\ :sub:`11`. The Cr data, just like the Cb plane, 35is in the third plane. 36 37``V4L2_PIX_FMT_YVU420M`` is the same except the Cr data is stored in the 38second plane and the Cb data in the third plane. 39 40If the Y plane has pad bytes after each row, then the Cb and Cr planes 41have half as many pad bytes after their rows. In other words, two Cx 42rows (including padding) is exactly as long as one Y row (including 43padding). 44 45``V4L2_PIX_FMT_YUV420M`` and ``V4L2_PIX_FMT_YVU420M`` are intended to be 46used only in drivers and applications that support the multi-planar API, 47described in :ref:`planar-apis`. 48 49**Byte Order.** 50Each cell is one byte. 51 52 53 54 55.. flat-table:: 56 :header-rows: 0 57 :stub-columns: 0 58 59 * - start0 + 0: 60 - Y'\ :sub:`00` 61 - Y'\ :sub:`01` 62 - Y'\ :sub:`02` 63 - Y'\ :sub:`03` 64 * - start0 + 4: 65 - Y'\ :sub:`10` 66 - Y'\ :sub:`11` 67 - Y'\ :sub:`12` 68 - Y'\ :sub:`13` 69 * - start0 + 8: 70 - Y'\ :sub:`20` 71 - Y'\ :sub:`21` 72 - Y'\ :sub:`22` 73 - Y'\ :sub:`23` 74 * - start0 + 12: 75 - Y'\ :sub:`30` 76 - Y'\ :sub:`31` 77 - Y'\ :sub:`32` 78 - Y'\ :sub:`33` 79 * - 80 * - start1 + 0: 81 - Cb\ :sub:`00` 82 - Cb\ :sub:`01` 83 * - start1 + 2: 84 - Cb\ :sub:`10` 85 - Cb\ :sub:`11` 86 * - 87 * - start2 + 0: 88 - Cr\ :sub:`00` 89 - Cr\ :sub:`01` 90 * - start2 + 2: 91 - Cr\ :sub:`10` 92 - Cr\ :sub:`11` 93 94 95**Color Sample Location:** 96 97 98 99.. flat-table:: 100 :header-rows: 0 101 :stub-columns: 0 102 103 * - 104 - 0 105 - 106 - 1 107 - 108 - 2 109 - 110 - 3 111 * - 0 112 - Y 113 - 114 - Y 115 - 116 - Y 117 - 118 - Y 119 * - 120 - 121 - C 122 - 123 - 124 - 125 - C 126 - 127 * - 1 128 - Y 129 - 130 - Y 131 - 132 - Y 133 - 134 - Y 135 * - 136 * - 2 137 - Y 138 - 139 - Y 140 - 141 - Y 142 - 143 - Y 144 * - 145 - 146 - C 147 - 148 - 149 - 150 - C 151 - 152 * - 3 153 - Y 154 - 155 - Y 156 - 157 - Y 158 - 159 - Y 160