Documentation/linux_tv/media/v4l/pixfmt-nv12.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _V4L2-PIX-FMT-NV12:
   4
   5 ******************************************************
   6 V4L2_PIX_FMT_NV12 ('NV12'), V4L2_PIX_FMT_NV21 ('NV21')
   7 ******************************************************
   8
   9 *man V4L2_PIX_FMT_NV12(2)*
  10
  11 V4L2_PIX_FMT_NV21
  12 Formats with ½ horizontal and vertical chroma resolution, also known as
  13 YUV 4:2:0. One luminance and one chrominance plane with alternating
  14 chroma samples as opposed to ``V4L2_PIX_FMT_YVU420``
  15
  16
  17 Description
  18 ===========
  19
  20 These are two-plane versions of the YUV 4:2:0 format. The three
  21 components are separated into two sub-images or planes. The Y plane is
  22 first. The Y plane has one byte per pixel. For ``V4L2_PIX_FMT_NV12``, a
  23 combined CbCr plane immediately follows the Y plane in memory. The CbCr
  24 plane is the same width, in bytes, as the Y plane (and of the image),
  25 but is half as tall in pixels. Each CbCr pair belongs to four pixels.
  26 For example, Cb\ :sub:`0`/Cr:sub:`0` belongs to Y'\ :sub:`00`,
  27 Y'\ :sub:`01`, Y'\ :sub:`10`, Y'\ :sub:`11`. ``V4L2_PIX_FMT_NV21`` is
  28 the same except the Cb and Cr bytes are swapped, the CrCb plane starts
  29 with a Cr byte.
  30
  31 If the Y plane has pad bytes after each row, then the CbCr plane has as
  32 many pad bytes after its rows.
  33
  34 **Byte Order..**
  35
  36 Each cell is one byte.
  37
  38
  39
  40 .. flat-table::
  41     :header-rows:  0
  42     :stub-columns: 0
  43     :widths:       2 1 1 1 1
  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        -  Cb\ :sub:`00`
  99
 100        -  Cr\ :sub:`00`
 101
 102        -  Cb\ :sub:`01`
 103
 104        -  Cr\ :sub:`01`
 105
 106     -  .. row 6
 107
 108        -  start + 20:
 109
 110        -  Cb\ :sub:`10`
 111
 112        -  Cr\ :sub:`10`
 113
 114        -  Cb\ :sub:`11`
 115
 116        -  Cr\ :sub:`11`
 117
 118
 119 **Color Sample Location..**
 120
 121
 122
 123 .. flat-table::
 124     :header-rows:  0
 125     :stub-columns: 0
 126
 127
 128     -  .. row 1
 129
 130        -
 131        -  0
 132
 133        -
 134        -  1
 135
 136        -
 137        -  2
 138
 139        -
 140        -  3
 141
 142     -  .. row 2
 143
 144        -  0
 145
 146        -  Y
 147
 148        -
 149        -  Y
 150
 151        -
 152        -  Y
 153
 154        -
 155        -  Y
 156
 157     -  .. row 3
 158
 159        -
 160        -
 161        -  C
 162
 163        -
 164        -
 165        -
 166        -  C
 167
 168        -
 169
 170     -  .. row 4
 171
 172        -  1
 173
 174        -  Y
 175
 176        -
 177        -  Y
 178
 179        -
 180        -  Y
 181
 182        -
 183        -  Y
 184
 185     -  .. row 5
 186
 187        -
 188
 189     -  .. row 6
 190
 191        -  2
 192
 193        -  Y
 194
 195        -
 196        -  Y
 197
 198        -
 199        -  Y
 200
 201        -
 202        -  Y
 203
 204     -  .. row 7
 205
 206        -
 207        -
 208        -  C
 209
 210        -
 211        -
 212        -
 213        -  C
 214
 215        -
 216
 217     -  .. row 8
 218
 219        -  3
 220
 221        -  Y
 222
 223        -
 224        -  Y
 225
 226        -
 227        -  Y
 228
 229        -
 230        -  Y
 231
 232
 233
 234
 235 .. ------------------------------------------------------------------------------
 236 .. This file was automatically converted from DocBook-XML with the dbxml
 237 .. library (https://github.com/return42/sphkerneldoc). The origin XML comes
 238 .. from the linux kernel, refer to:
 239 ..
 240 .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
 241 .. ------------------------------------------------------------------------------