Documentation/linux_tv/media/v4l/pixfmt-yuv420.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _V4L2-PIX-FMT-YVU420:
   4
   5 **********************************************************
   6 V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')
   7 **********************************************************
   8
   9 *man V4L2_PIX_FMT_YVU420(2)*
  10
  11 V4L2_PIX_FMT_YUV420
  12 Planar formats with ½ horizontal and vertical chroma resolution, also
  13 known as YUV 4:2:0
  14
  15
  16 Description
  17 ===========
  18
  19 These are planar formats, as opposed to a packed format. The three
  20 components are separated into three sub- images or planes. The Y plane
  21 is first. The Y plane has one byte per pixel. For
  22 ``V4L2_PIX_FMT_YVU420``, the Cr plane immediately follows the Y plane in
  23 memory. The Cr plane is half the width and half the height of the Y
  24 plane (and of the image). Each Cr belongs to four pixels, a two-by-two
  25 square of the image. For example, Cr\ :sub:`0` belongs to Y'\ :sub:`00`,
  26 Y'\ :sub:`01`, Y'\ :sub:`10`, and Y'\ :sub:`11`. Following the Cr plane
  27 is the Cb plane, just like the Cr plane. ``V4L2_PIX_FMT_YUV420`` is the
  28 same except the Cb plane comes first, then the Cr plane.
  29
  30 If the Y plane has pad bytes after each row, then the Cr and Cb planes
  31 have half as many pad bytes after their rows. In other words, two Cx
  32 rows (including padding) is exactly as long as one Y row (including
  33 padding).
  34
  35 **Byte Order..**
  36
  37 Each cell is one byte.
  38
  39
  40
  41 .. flat-table::
  42     :header-rows:  0
  43     :stub-columns: 0
  44     :widths:       2 1 1 1 1
  45
  46
  47     -  .. row 1
  48
  49        -  start + 0:
  50
  51        -  Y'\ :sub:`00`
  52
  53        -  Y'\ :sub:`01`
  54
  55        -  Y'\ :sub:`02`
  56
  57        -  Y'\ :sub:`03`
  58
  59     -  .. row 2
  60
  61        -  start + 4:
  62
  63        -  Y'\ :sub:`10`
  64
  65        -  Y'\ :sub:`11`
  66
  67        -  Y'\ :sub:`12`
  68
  69        -  Y'\ :sub:`13`
  70
  71     -  .. row 3
  72
  73        -  start + 8:
  74
  75        -  Y'\ :sub:`20`
  76
  77        -  Y'\ :sub:`21`
  78
  79        -  Y'\ :sub:`22`
  80
  81        -  Y'\ :sub:`23`
  82
  83     -  .. row 4
  84
  85        -  start + 12:
  86
  87        -  Y'\ :sub:`30`
  88
  89        -  Y'\ :sub:`31`
  90
  91        -  Y'\ :sub:`32`
  92
  93        -  Y'\ :sub:`33`
  94
  95     -  .. row 5
  96
  97        -  start + 16:
  98
  99        -  Cr\ :sub:`00`
 100
 101        -  Cr\ :sub:`01`
 102
 103     -  .. row 6
 104
 105        -  start + 18:
 106
 107        -  Cr\ :sub:`10`
 108
 109        -  Cr\ :sub:`11`
 110
 111     -  .. row 7
 112
 113        -  start + 20:
 114
 115        -  Cb\ :sub:`00`
 116
 117        -  Cb\ :sub:`01`
 118
 119     -  .. row 8
 120
 121        -  start + 22:
 122
 123        -  Cb\ :sub:`10`
 124
 125        -  Cb\ :sub:`11`
 126
 127
 128 **Color Sample Location..**
 129
 130
 131
 132 .. flat-table::
 133     :header-rows:  0
 134     :stub-columns: 0
 135
 136
 137     -  .. row 1
 138
 139        -
 140        -  0
 141
 142        -
 143        -  1
 144
 145        -
 146        -  2
 147
 148        -
 149        -  3
 150
 151     -  .. row 2
 152
 153        -  0
 154
 155        -  Y
 156
 157        -
 158        -  Y
 159
 160        -
 161        -  Y
 162
 163        -
 164        -  Y
 165
 166     -  .. row 3
 167
 168        -
 169        -
 170        -  C
 171
 172        -
 173        -
 174        -
 175        -  C
 176
 177        -
 178
 179     -  .. row 4
 180
 181        -  1
 182
 183        -  Y
 184
 185        -
 186        -  Y
 187
 188        -
 189        -  Y
 190
 191        -
 192        -  Y
 193
 194     -  .. row 5
 195
 196        -
 197
 198     -  .. row 6
 199
 200        -  2
 201
 202        -  Y
 203
 204        -
 205        -  Y
 206
 207        -
 208        -  Y
 209
 210        -
 211        -  Y
 212
 213     -  .. row 7
 214
 215        -
 216        -
 217        -  C
 218
 219        -
 220        -
 221        -
 222        -  C
 223
 224        -
 225
 226     -  .. row 8
 227
 228        -  3
 229
 230        -  Y
 231
 232        -
 233        -  Y
 234
 235        -
 236        -  Y
 237
 238        -
 239        -  Y
 240
 241
 242
 243
 244 .. ------------------------------------------------------------------------------
 245 .. This file was automatically converted from DocBook-XML with the dbxml
 246 .. library (https://github.com/return42/sphkerneldoc). The origin XML comes
 247 .. from the linux kernel, refer to:
 248 ..
 249 .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
 250 .. ------------------------------------------------------------------------------