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

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _V4L2-PIX-FMT-NV12:
   4 .. _V4L2-PIX-FMT-NV21:
   5
   6 ******************************************************
   7 V4L2_PIX_FMT_NV12 ('NV12'), V4L2_PIX_FMT_NV21 ('NV21')
   8 ******************************************************
   9
  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 Each cell is one byte.
  36
  37
  38 .. flat-table::
  39     :header-rows:  0
  40     :stub-columns: 0
  41
  42     -  .. row 1
  43
  44        -  start + 0:
  45
  46        -  Y'\ :sub:`00`
  47
  48        -  Y'\ :sub:`01`
  49
  50        -  Y'\ :sub:`02`
  51
  52        -  Y'\ :sub:`03`
  53
  54     -  .. row 2
  55
  56        -  start + 4:
  57
  58        -  Y'\ :sub:`10`
  59
  60        -  Y'\ :sub:`11`
  61
  62        -  Y'\ :sub:`12`
  63
  64        -  Y'\ :sub:`13`
  65
  66     -  .. row 3
  67
  68        -  start + 8:
  69
  70        -  Y'\ :sub:`20`
  71
  72        -  Y'\ :sub:`21`
  73
  74        -  Y'\ :sub:`22`
  75
  76        -  Y'\ :sub:`23`
  77
  78     -  .. row 4
  79
  80        -  start + 12:
  81
  82        -  Y'\ :sub:`30`
  83
  84        -  Y'\ :sub:`31`
  85
  86        -  Y'\ :sub:`32`
  87
  88        -  Y'\ :sub:`33`
  89
  90     -  .. row 5
  91
  92        -  start + 16:
  93
  94        -  Cb\ :sub:`00`
  95
  96        -  Cr\ :sub:`00`
  97
  98        -  Cb\ :sub:`01`
  99
 100        -  Cr\ :sub:`01`
 101
 102     -  .. row 6
 103
 104        -  start + 20:
 105
 106        -  Cb\ :sub:`10`
 107
 108        -  Cr\ :sub:`10`
 109
 110        -  Cb\ :sub:`11`
 111
 112        -  Cr\ :sub:`11`
 113
 114
 115 **Color Sample Location..**
 116
 117 .. flat-table::
 118     :header-rows:  0
 119     :stub-columns: 0
 120
 121
 122     -  .. row 1
 123
 124        -
 125        -  0
 126
 127        -
 128        -  1
 129
 130        -  2
 131
 132        -
 133        -  3
 134
 135     -  .. row 2
 136
 137        -  0
 138
 139        -  Y
 140
 141        -
 142        -  Y
 143
 144        -  Y
 145
 146        -
 147        -  Y
 148
 149     -  .. row 3
 150
 151        -
 152        -
 153        -  C
 154
 155        -
 156        -
 157        -  C
 158
 159        -
 160
 161     -  .. row 4
 162
 163        -  1
 164
 165        -  Y
 166        -
 167
 168        -  Y
 169
 170        -  Y
 171
 172        -
 173        -  Y
 174
 175     -  .. row 5
 176
 177        -
 178
 179     -  .. row 6
 180
 181        -  2
 182
 183        -  Y
 184        -
 185
 186        -  Y
 187
 188        -  Y
 189
 190        -
 191        -  Y
 192
 193     -  .. row 7
 194
 195        -
 196        -
 197        -  C
 198
 199        -
 200        -
 201        -  C
 202
 203        -
 204
 205     -  .. row 8
 206
 207        -  3
 208
 209        -  Y
 210
 211        -
 212        -  Y
 213
 214        -  Y
 215
 216        -
 217        -  Y