Documentation/media/uapi/v4l/pixfmt-yuv420m.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _V4L2-PIX-FMT-YUV420M:
   4 .. _v4l2-pix-fmt-yvu420m:
   5
   6 ************************************************************
   7 V4L2_PIX_FMT_YUV420M ('YM12'), V4L2_PIX_FMT_YVU420M ('YM21')
   8 ************************************************************
   9
  10 *man V4L2_PIX_FMT_YUV420M(2)*
  11
  12 V4L2_PIX_FMT_YVU420M
  13 Variation of ``V4L2_PIX_FMT_YUV420`` and ``V4L2_PIX_FMT_YVU420`` with
  14 planes non contiguous in memory.
  15
  16
  17 Description
  18 ===========
  19
  20 This is a multi-planar format, as opposed to a packed format. The three
  21 components are separated into three sub-images or planes.
  22
  23 The Y plane is first. The Y plane has one byte per pixel. For
  24 ``V4L2_PIX_FMT_YUV420M`` the Cb data constitutes the second plane which
  25 is half the width and half the height of the Y plane (and of the image).
  26 Each Cb belongs to four pixels, a two-by-two square of the image. For
  27 example, Cb\ :sub:`0` belongs to Y'\ :sub:`00`, Y'\ :sub:`01`,
  28 Y'\ :sub:`10`, and Y'\ :sub:`11`. The Cr data, just like the Cb plane,
  29 is in the third plane.
  30
  31 ``V4L2_PIX_FMT_YVU420M`` is the same except the Cr data is stored in the
  32 second plane and the Cb data in the third plane.
  33
  34 If the Y plane has pad bytes after each row, then the Cb and Cr planes
  35 have half as many pad bytes after their rows. In other words, two Cx
  36 rows (including padding) is exactly as long as one Y row (including
  37 padding).
  38
  39 ``V4L2_PIX_FMT_YUV420M`` and ``V4L2_PIX_FMT_YVU420M`` are intended to be
  40 used only in drivers and applications that support the multi-planar API,
  41 described in :ref:`planar-apis`.
  42
  43 **Byte Order.**
  44 Each cell is one byte.
  45
  46
  47
  48 .. flat-table::
  49     :header-rows:  0
  50     :stub-columns: 0
  51     :widths:       2 1 1 1 1
  52
  53
  54     -  .. row 1
  55
  56        -  start0 + 0:
  57
  58        -  Y'\ :sub:`00`
  59
  60        -  Y'\ :sub:`01`
  61
  62        -  Y'\ :sub:`02`
  63
  64        -  Y'\ :sub:`03`
  65
  66     -  .. row 2
  67
  68        -  start0 + 4:
  69
  70        -  Y'\ :sub:`10`
  71
  72        -  Y'\ :sub:`11`
  73
  74        -  Y'\ :sub:`12`
  75
  76        -  Y'\ :sub:`13`
  77
  78     -  .. row 3
  79
  80        -  start0 + 8:
  81
  82        -  Y'\ :sub:`20`
  83
  84        -  Y'\ :sub:`21`
  85
  86        -  Y'\ :sub:`22`
  87
  88        -  Y'\ :sub:`23`
  89
  90     -  .. row 4
  91
  92        -  start0 + 12:
  93
  94        -  Y'\ :sub:`30`
  95
  96        -  Y'\ :sub:`31`
  97
  98        -  Y'\ :sub:`32`
  99
 100        -  Y'\ :sub:`33`
 101
 102     -  .. row 5
 103
 104        -
 105
 106     -  .. row 6
 107
 108        -  start1 + 0:
 109
 110        -  Cb\ :sub:`00`
 111
 112        -  Cb\ :sub:`01`
 113
 114     -  .. row 7
 115
 116        -  start1 + 2:
 117
 118        -  Cb\ :sub:`10`
 119
 120        -  Cb\ :sub:`11`
 121
 122     -  .. row 8
 123
 124        -
 125
 126     -  .. row 9
 127
 128        -  start2 + 0:
 129
 130        -  Cr\ :sub:`00`
 131
 132        -  Cr\ :sub:`01`
 133
 134     -  .. row 10
 135
 136        -  start2 + 2:
 137
 138        -  Cr\ :sub:`10`
 139
 140        -  Cr\ :sub:`11`
 141
 142
 143 **Color Sample Location..**
 144
 145
 146
 147 .. flat-table::
 148     :header-rows:  0
 149     :stub-columns: 0
 150
 151
 152     -  .. row 1
 153
 154        -
 155        -  0
 156
 157        -
 158        -  1
 159
 160        -
 161        -  2
 162
 163        -
 164        -  3
 165
 166     -  .. row 2
 167
 168        -  0
 169
 170        -  Y
 171
 172        -
 173        -  Y
 174
 175        -
 176        -  Y
 177
 178        -
 179        -  Y
 180
 181     -  .. row 3
 182
 183        -
 184        -
 185        -  C
 186
 187        -
 188        -
 189        -
 190        -  C
 191
 192        -
 193
 194     -  .. row 4
 195
 196        -  1
 197
 198        -  Y
 199
 200        -
 201        -  Y
 202
 203        -
 204        -  Y
 205
 206        -
 207        -  Y
 208
 209     -  .. row 5
 210
 211        -
 212
 213     -  .. row 6
 214
 215        -  2
 216
 217        -  Y
 218
 219        -
 220        -  Y
 221
 222        -
 223        -  Y
 224
 225        -
 226        -  Y
 227
 228     -  .. row 7
 229
 230        -
 231        -
 232        -  C
 233
 234        -
 235        -
 236        -
 237        -  C
 238
 239        -
 240
 241     -  .. row 8
 242
 243        -  3
 244
 245        -  Y
 246
 247        -
 248        -  Y
 249
 250        -
 251        -  Y
 252
 253        -
 254        -  Y