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 *man V4L2_PIX_FMT_NV12(2)*
  11
  12 V4L2_PIX_FMT_NV21
  13 Formats with ½ horizontal and vertical chroma resolution, also known as
  14 YUV 4:2:0. One luminance and one chrominance plane with alternating
  15 chroma samples as opposed to ``V4L2_PIX_FMT_YVU420``
  16
  17
  18 Description
  19 ===========
  20
  21 These are two-plane versions of the YUV 4:2:0 format. The three
  22 components are separated into two sub-images or planes. The Y plane is
  23 first. The Y plane has one byte per pixel. For ``V4L2_PIX_FMT_NV12``, a
  24 combined CbCr plane immediately follows the Y plane in memory. The CbCr
  25 plane is the same width, in bytes, as the Y plane (and of the image),
  26 but is half as tall in pixels. Each CbCr pair belongs to four pixels.
  27 For example, Cb\ :sub:`0`/Cr\ :sub:`0` belongs to Y'\ :sub:`00`,
  28 Y'\ :sub:`01`, Y'\ :sub:`10`, Y'\ :sub:`11`. ``V4L2_PIX_FMT_NV21`` is
  29 the same except the Cb and Cr bytes are swapped, the CrCb plane starts
  30 with a Cr byte.
  31
  32 If the Y plane has pad bytes after each row, then the CbCr plane has as
  33 many pad bytes after its rows.
  34
  35 **Byte Order.**
  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 .. flat-table::
 122     :header-rows:  0
 123     :stub-columns: 0
 124
 125
 126     -  .. row 1
 127
 128        -
 129        -  0
 130
 131        -
 132        -  1
 133
 134        -  2
 135
 136        -
 137        -  3
 138
 139     -  .. row 2
 140
 141        -  0
 142
 143        -  Y
 144
 145        -
 146        -  Y
 147
 148        -  Y
 149
 150        -
 151        -  Y
 152
 153     -  .. row 3
 154
 155        -
 156        -
 157        -  C
 158
 159        -
 160        -
 161        -  C
 162
 163        -
 164
 165     -  .. row 4
 166
 167        -  1
 168
 169        -  Y
 170        -
 171
 172        -  Y
 173
 174        -  Y
 175
 176        -
 177        -  Y
 178
 179     -  .. row 5
 180
 181        -
 182
 183     -  .. row 6
 184
 185        -  2
 186
 187        -  Y
 188        -
 189
 190        -  Y
 191
 192        -  Y
 193
 194        -
 195        -  Y
 196
 197     -  .. row 7
 198
 199        -
 200        -
 201        -  C
 202
 203        -
 204        -
 205        -  C
 206
 207        -
 208
 209     -  .. row 8
 210
 211        -  3
 212
 213        -  Y
 214
 215        -
 216        -  Y
 217
 218        -  Y
 219
 220        -
 221        -  Y