1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2 3.. _packed-yuv: 4 5****************** 6Packed YUV formats 7****************** 8 9Similarly to the packed RGB formats, the packed YUV formats store the Y, Cb and 10Cr components consecutively in memory. They may apply subsampling to the chroma 11components and thus differ in how they interlave the three components. 12 13.. note:: 14 15 - In all the tables that follow, bit 7 is the most significant bit in a byte. 16 - 'Y', 'Cb' and 'Cr' denote bits of the luma, blue chroma (also known as 17 'U') and red chroma (also known as 'V') components respectively. 'A' 18 denotes bits of the alpha component (if supported by the format), and 'X' 19 denotes padding bits. 20 21 224:4:4 Subsampling 23================= 24 25These formats do not subsample the chroma components and store each pixels as a 26full triplet of Y, Cb and Cr values. 27 28The next table lists the packed YUV 4:4:4 formats with less than 8 bits per 29component. They are named based on the order of the Y, Cb and Cr components as 30seen in a 16-bit word, which is then stored in memory in little endian byte 31order, and on the number of bits for each component. For instance the YUV565 32format stores a pixel in a 16-bit word [15:0] laid out at as [Y'\ :sub:`4-0` 33Cb\ :sub:`5-0` Cr\ :sub:`4-0`], and stored in memory in two bytes, 34[Cb\ :sub:`2-0` Cr\ :sub:`4-0`] followed by [Y'\ :sub:`4-0` Cb\ :sub:`5-3`]. 35 36.. raw:: latex 37 38 \begingroup 39 \tiny 40 \setlength{\tabcolsep}{2pt} 41 42.. tabularcolumns:: |p{2.5cm}|p{0.69cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}|p{0.31cm}| 43 44.. flat-table:: Packed YUV 4:4:4 Image Formats (less than 8bpc) 45 :header-rows: 2 46 :stub-columns: 0 47 48 * - Identifier 49 - Code 50 51 - :cspan:`7` Byte 0 in memory 52 53 - :cspan:`7` Byte 1 54 55 * - 56 - 57 - 7 58 - 6 59 - 5 60 - 4 61 - 3 62 - 2 63 - 1 64 - 0 65 66 - 7 67 - 6 68 - 5 69 - 4 70 - 3 71 - 2 72 - 1 73 - 0 74 75 * .. _V4L2-PIX-FMT-YUV444: 76 77 - ``V4L2_PIX_FMT_YUV444`` 78 - 'Y444' 79 80 - Cb\ :sub:`3` 81 - Cb\ :sub:`2` 82 - Cb\ :sub:`1` 83 - Cb\ :sub:`0` 84 - Cr\ :sub:`3` 85 - Cr\ :sub:`2` 86 - Cr\ :sub:`1` 87 - Cr\ :sub:`0` 88 89 - a\ :sub:`3` 90 - a\ :sub:`2` 91 - a\ :sub:`1` 92 - a\ :sub:`0` 93 - Y'\ :sub:`3` 94 - Y'\ :sub:`2` 95 - Y'\ :sub:`1` 96 - Y'\ :sub:`0` 97 98 * .. _V4L2-PIX-FMT-YUV555: 99 100 - ``V4L2_PIX_FMT_YUV555`` 101 - 'YUVO' 102 103 - Cb\ :sub:`2` 104 - Cb\ :sub:`1` 105 - Cb\ :sub:`0` 106 - Cr\ :sub:`4` 107 - Cr\ :sub:`3` 108 - Cr\ :sub:`2` 109 - Cr\ :sub:`1` 110 - Cr\ :sub:`0` 111 112 - a 113 - Y'\ :sub:`4` 114 - Y'\ :sub:`3` 115 - Y'\ :sub:`2` 116 - Y'\ :sub:`1` 117 - Y'\ :sub:`0` 118 - Cb\ :sub:`4` 119 - Cb\ :sub:`3` 120 121 * .. _V4L2-PIX-FMT-YUV565: 122 123 - ``V4L2_PIX_FMT_YUV565`` 124 - 'YUVP' 125 126 - Cb\ :sub:`2` 127 - Cb\ :sub:`1` 128 - Cb\ :sub:`0` 129 - Cr\ :sub:`4` 130 - Cr\ :sub:`3` 131 - Cr\ :sub:`2` 132 - Cr\ :sub:`1` 133 - Cr\ :sub:`0` 134 135 - Y'\ :sub:`4` 136 - Y'\ :sub:`3` 137 - Y'\ :sub:`2` 138 - Y'\ :sub:`1` 139 - Y'\ :sub:`0` 140 - Cb\ :sub:`5` 141 - Cb\ :sub:`4` 142 - Cb\ :sub:`3` 143 144.. raw:: latex 145 146 \endgroup 147 148.. note:: 149 150 For the YUV444 and YUV555 formats, the value of alpha bits is undefined 151 when reading from the driver, ignored when writing to the driver, except 152 when alpha blending has been negotiated for a :ref:`Video Overlay 153 <overlay>` or :ref:`Video Output Overlay <osd>`. 154 155 156The next table lists the packed YUV 4:4:4 formats with 8 bits per component. 157They are named based on the order of the Y, Cb and Cr components as stored in 158memory, and on the total number of bits per pixel. For instance, the VUYX32 159format stores a pixel with Cr\ :sub:`7-0` in the first byte, Cb\ :sub:`7-0` in 160the second byte and Y'\ :sub:`7-0` in the third byte. 161 162.. flat-table:: Packed YUV Image Formats (8bpc) 163 :header-rows: 1 164 :stub-columns: 0 165 166 * - Identifier 167 - Code 168 - Byte 0 169 - Byte 1 170 - Byte 2 171 - Byte 3 172 173 * .. _V4L2-PIX-FMT-YUV32: 174 175 - ``V4L2_PIX_FMT_YUV32`` 176 - 'YUV4' 177 178 - A\ :sub:`7-0` 179 - Y'\ :sub:`7-0` 180 - Cb\ :sub:`7-0` 181 - Cr\ :sub:`7-0` 182 183 * .. _V4L2-PIX-FMT-AYUV32: 184 185 - ``V4L2_PIX_FMT_AYUV32`` 186 - 'AYUV' 187 188 - A\ :sub:`7-0` 189 - Y'\ :sub:`7-0` 190 - Cb\ :sub:`7-0` 191 - Cr\ :sub:`7-0` 192 193 * .. _V4L2-PIX-FMT-XYUV32: 194 195 - ``V4L2_PIX_FMT_XYUV32`` 196 - 'XYUV' 197 198 - X\ :sub:`7-0` 199 - Y'\ :sub:`7-0` 200 - Cb\ :sub:`7-0` 201 - Cr\ :sub:`7-0` 202 203 * .. _V4L2-PIX-FMT-VUYA32: 204 205 - ``V4L2_PIX_FMT_VUYA32`` 206 - 'VUYA' 207 208 - Cr\ :sub:`7-0` 209 - Cb\ :sub:`7-0` 210 - Y'\ :sub:`7-0` 211 - A\ :sub:`7-0` 212 213 * .. _V4L2-PIX-FMT-VUYX32: 214 215 - ``V4L2_PIX_FMT_VUYX32`` 216 - 'VUYX' 217 218 - Cr\ :sub:`7-0` 219 - Cb\ :sub:`7-0` 220 - Y'\ :sub:`7-0` 221 - X\ :sub:`7-0` 222 223.. note:: 224 225 - The alpha component is expected to contain a meaningful value that can be 226 used by drivers and applications. 227 - The padding bits contain undefined values that must be ignored by all 228 applications and drivers. 229 230 2314:2:2 Subsampling 232================= 233 234These formats, commonly referred to as YUYV or YUY2, subsample the chroma 235components horizontally by 2, storing 2 pixels in 4 bytes. 236 237.. flat-table:: Packed YUV 4:2:2 Formats 238 :header-rows: 1 239 :stub-columns: 0 240 241 * - Identifier 242 - Code 243 - Byte 0 244 - Byte 1 245 - Byte 2 246 - Byte 3 247 - Byte 4 248 - Byte 5 249 - Byte 6 250 - Byte 7 251 * .. _V4L2-PIX-FMT-UYVY: 252 253 - ``V4L2_PIX_FMT_UYVY`` 254 - 'UYVY' 255 256 - Cb\ :sub:`0` 257 - Y'\ :sub:`0` 258 - Cr\ :sub:`0` 259 - Y'\ :sub:`1` 260 - Cb\ :sub:`2` 261 - Y'\ :sub:`2` 262 - Cr\ :sub:`2` 263 - Y'\ :sub:`3` 264 * .. _V4L2-PIX-FMT-VYUY: 265 266 - ``V4L2_PIX_FMT_VYUY`` 267 - 'VYUY' 268 269 - Cr\ :sub:`0` 270 - Y'\ :sub:`0` 271 - Cb\ :sub:`0` 272 - Y'\ :sub:`1` 273 - Cr\ :sub:`2` 274 - Y'\ :sub:`2` 275 - Cb\ :sub:`2` 276 - Y'\ :sub:`3` 277 * .. _V4L2-PIX-FMT-YUYV: 278 279 - ``V4L2_PIX_FMT_YUYV`` 280 - 'YUYV' 281 282 - Y'\ :sub:`0` 283 - Cb\ :sub:`0` 284 - Y'\ :sub:`1` 285 - Cr\ :sub:`0` 286 - Y'\ :sub:`2` 287 - Cb\ :sub:`2` 288 - Y'\ :sub:`3` 289 - Cr\ :sub:`2` 290 * .. _V4L2-PIX-FMT-YVYU: 291 292 - ``V4L2_PIX_FMT_YVYU`` 293 - 'YVYU' 294 295 - Y'\ :sub:`0` 296 - Cr\ :sub:`0` 297 - Y'\ :sub:`1` 298 - Cb\ :sub:`0` 299 - Y'\ :sub:`2` 300 - Cr\ :sub:`2` 301 - Y'\ :sub:`3` 302 - Cb\ :sub:`2` 303 304**Color Sample Location:** 305Chroma samples are :ref:`interstitially sited<yuv-chroma-centered>` 306horizontally. 307 308 3094:1:1 Subsampling 310================= 311 312This format subsamples the chroma components horizontally by 4, storing 8 313pixels in 12 bytes. 314 315.. flat-table:: Packed YUV 4:1:1 Formats 316 :header-rows: 1 317 :stub-columns: 0 318 319 * - Identifier 320 - Code 321 - Byte 0 322 - Byte 1 323 - Byte 2 324 - Byte 3 325 - Byte 4 326 - Byte 5 327 - Byte 6 328 - Byte 7 329 - Byte 8 330 - Byte 9 331 - Byte 10 332 - Byte 11 333 * .. _V4L2-PIX-FMT-Y41P: 334 335 - ``V4L2_PIX_FMT_Y41P`` 336 - 'Y41P' 337 338 - Cb\ :sub:`0` 339 - Y'\ :sub:`0` 340 - Cr\ :sub:`0` 341 - Y'\ :sub:`1` 342 - Cb\ :sub:`4` 343 - Y'\ :sub:`2` 344 - Cr\ :sub:`4` 345 - Y'\ :sub:`3` 346 - Y'\ :sub:`4` 347 - Y'\ :sub:`5` 348 - Y'\ :sub:`6` 349 - Y'\ :sub:`7` 350 351.. note:: 352 353 Do not confuse ``V4L2_PIX_FMT_Y41P`` with 354 :ref:`V4L2_PIX_FMT_YUV411P <V4L2-PIX-FMT-YUV411P>`. Y41P is derived from 355 "YUV 4:1:1 *packed*", while YUV411P stands for "YUV 4:1:1 *planar*". 356 357**Color Sample Location:** 358Chroma samples are :ref:`interstitially sited<yuv-chroma-centered>` 359horizontally. 360