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

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _V4L2-PIX-FMT-YVU420:
   4 .. _V4L2-PIX-FMT-YUV420:
   5
   6 **********************************************************
   7 V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')
   8 **********************************************************
   9
  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 Each cell is one byte.
  37
  38
  39
  40
  41 .. flat-table::
  42     :header-rows:  0
  43     :stub-columns: 0
  44
  45
  46     -  .. row 1
  47
  48        -  start + 0:
  49
  50        -  Y'\ :sub:`00`
  51
  52        -  Y'\ :sub:`01`
  53
  54        -  Y'\ :sub:`02`
  55
  56        -  Y'\ :sub:`03`
  57
  58     -  .. row 2
  59
  60        -  start + 4:
  61
  62        -  Y'\ :sub:`10`
  63
  64        -  Y'\ :sub:`11`
  65
  66        -  Y'\ :sub:`12`
  67
  68        -  Y'\ :sub:`13`
  69
  70     -  .. row 3
  71
  72        -  start + 8:
  73
  74        -  Y'\ :sub:`20`
  75
  76        -  Y'\ :sub:`21`
  77
  78        -  Y'\ :sub:`22`
  79
  80        -  Y'\ :sub:`23`
  81
  82     -  .. row 4
  83
  84        -  start + 12:
  85
  86        -  Y'\ :sub:`30`
  87
  88        -  Y'\ :sub:`31`
  89
  90        -  Y'\ :sub:`32`
  91
  92        -  Y'\ :sub:`33`
  93
  94     -  .. row 5
  95
  96        -  start + 16:
  97
  98        -  Cr\ :sub:`00`
  99
 100        -  Cr\ :sub:`01`
 101
 102     -  .. row 6
 103
 104        -  start + 18:
 105
 106        -  Cr\ :sub:`10`
 107
 108        -  Cr\ :sub:`11`
 109
 110     -  .. row 7
 111
 112        -  start + 20:
 113
 114        -  Cb\ :sub:`00`
 115
 116        -  Cb\ :sub:`01`
 117
 118     -  .. row 8
 119
 120        -  start + 22:
 121
 122        -  Cb\ :sub:`10`
 123
 124        -  Cb\ :sub:`11`
 125
 126
 127 **Color Sample Location..**
 128
 129
 130
 131 .. flat-table::
 132     :header-rows:  0
 133     :stub-columns: 0
 134
 135
 136     -  .. row 1
 137
 138        -
 139        -  0
 140
 141        -
 142        -  1
 143
 144        -
 145        -  2
 146
 147        -
 148        -  3
 149
 150     -  .. row 2
 151
 152        -  0
 153
 154        -  Y
 155
 156        -
 157        -  Y
 158
 159        -
 160        -  Y
 161
 162        -
 163        -  Y
 164
 165     -  .. row 3
 166
 167        -
 168        -
 169        -  C
 170
 171        -
 172        -
 173        -
 174        -  C
 175
 176        -
 177
 178     -  .. row 4
 179
 180        -  1
 181
 182        -  Y
 183
 184        -
 185        -  Y
 186
 187        -
 188        -  Y
 189
 190        -
 191        -  Y
 192
 193     -  .. row 5
 194
 195        -
 196
 197     -  .. row 6
 198
 199        -  2
 200
 201        -  Y
 202
 203        -
 204        -  Y
 205
 206        -
 207        -  Y
 208
 209        -
 210        -  Y
 211
 212     -  .. row 7
 213
 214        -
 215        -
 216        -  C
 217
 218        -
 219        -
 220        -
 221        -  C
 222
 223        -
 224
 225     -  .. row 8
 226
 227        -  3
 228
 229        -  Y
 230
 231        -
 232        -  Y
 233
 234        -
 235        -  Y
 236
 237        -
 238        -  Y