1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> 2 <HTML 3 ><HEAD 4 ><TITLE 5 >V4L2_PIX_FMT_NV12 ('NV12'), V4L2_PIX_FMT_NV21 ('NV21')</TITLE 6 ><META 7 NAME="GENERATOR" 8 CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK 9 REL="HOME" 10 TITLE="Video for Linux Two API Specification" 11 HREF="book1.htm"><LINK 12 REL="UP" 13 TITLE="YUV Formats" 14 HREF="x3891.htm"><LINK 15 REL="PREVIOUS" 16 TITLE="V4L2_PIX_FMT_YUV411P ('411P')" 17 HREF="r5319.htm"><LINK 18 REL="NEXT" 19 TITLE="Compressed Formats" 20 HREF="x5634.htm"></HEAD 21 ><BODY 22 CLASS="REFENTRY" 23 BGCOLOR="#FFFFFF" 24 TEXT="#000000" 25 LINK="#0000FF" 26 VLINK="#840084" 27 ALINK="#0000FF" 28 ><DIV 29 CLASS="NAVHEADER" 30 ><TABLE 31 SUMMARY="Header navigation table" 32 WIDTH="100%" 33 BORDER="0" 34 CELLPADDING="0" 35 CELLSPACING="0" 36 ><TR 37 ><TH 38 COLSPAN="3" 39 ALIGN="center" 40 >Video for Linux Two API Specification: Revision 0.24</TH 41 ></TR 42 ><TR 43 ><TD 44 WIDTH="10%" 45 ALIGN="left" 46 VALIGN="bottom" 47 ><A 48 HREF="r5319.htm" 49 ACCESSKEY="P" 50 >Prev</A 51 ></TD 52 ><TD 53 WIDTH="80%" 54 ALIGN="center" 55 VALIGN="bottom" 56 ></TD 57 ><TD 58 WIDTH="10%" 59 ALIGN="right" 60 VALIGN="bottom" 61 ><A 62 HREF="x5634.htm" 63 ACCESSKEY="N" 64 >Next</A 65 ></TD 66 ></TR 67 ></TABLE 68 ><HR 69 ALIGN="LEFT" 70 WIDTH="100%"></DIV 71 ><H1 72 ><A 73 NAME="AEN5470" 74 ></A 75 >V4L2_PIX_FMT_NV12 ('NV12'), V4L2_PIX_FMT_NV21 ('NV21')</H1 76 ><DIV 77 CLASS="REFNAMEDIV" 78 ><A 79 NAME="AEN5474" 80 ></A 81 ><H2 82 >Name</H2 83 ><CODE 84 CLASS="CONSTANT" 85 >V4L2_PIX_FMT_NV12</CODE 86 >, <CODE 87 CLASS="CONSTANT" 88 >V4L2_PIX_FMT_NV21</CODE 89 > -- Formats with ½ horizontal and vertical 90 chroma resolution, also known as YUV 4:2:0. One luminance and one 91 chrominance plane with alternating chroma samples as opposed to 92 <CODE 93 CLASS="CONSTANT" 94 >V4L2_PIX_FMT_YVU420</CODE 95 ></DIV 96 ><DIV 97 CLASS="REFSECT1" 98 ><A 99 NAME="AEN5481" 100 ></A 101 ><H2 102 >Description</H2 103 ><P 104 >These are two-plane versions of the YUV 4:2:0 format. 105 The three components are separated into two sub-images or planes. The 106 Y plane is first. The Y plane has one byte per pixel. For 107 <CODE 108 CLASS="CONSTANT" 109 >V4L2_PIX_FMT_NV12</CODE 110 >, a combined CbCr plane 111 immediately follows the Y plane in memory. The CbCr plane is the same 112 width, in bytes, as the Y plane (and of the image), but is half as 113 tall in pixels. Each CbCr pair belongs to four pixels. For example, 114 Cb<SUB 115 >0</SUB 116 >/Cr<SUB 117 >0</SUB 118 > belongs to 119 Y'<SUB 120 >00</SUB 121 >, Y'<SUB 122 >01</SUB 123 >, 124 Y'<SUB 125 >10</SUB 126 >, Y'<SUB 127 >11</SUB 128 >. 129 <CODE 130 CLASS="CONSTANT" 131 >V4L2_PIX_FMT_NV21</CODE 132 > is the same except the Cb and 133 Cr bytes are swapped, the CrCb plane starts with a Cr byte.</P 134 ><P 135 >If the Y plane has pad bytes after each row, then the 136 CbCr plane has as many pad bytes after its rows.</P 137 ><DIV 138 CLASS="EXAMPLE" 139 ><A 140 NAME="AEN5493" 141 ></A 142 ><P 143 ><B 144 >Example 2-1. <CODE 145 CLASS="CONSTANT" 146 >V4L2_PIX_FMT_NV12</CODE 147 > 4 × 4 148 pixel image</B 149 ></P 150 ><DIV 151 CLASS="FORMALPARA" 152 ><P 153 ><B 154 >Byte Order. </B 155 >Each cell is one byte. 156 <DIV 157 CLASS="INFORMALTABLE" 158 ><P 159 ></P 160 ><A 161 NAME="AEN5499" 162 ></A 163 ><TABLE 164 BORDER="0" 165 FRAME="void" 166 CLASS="CALSTABLE" 167 ><COL 168 WIDTH="2*" 169 ALIGN="LEFT"><COL><COL><COL><COL><TBODY 170 VALIGN="TOP" 171 ><TR 172 ><TD 173 >start + 0:</TD 174 ><TD 175 >Y'<SUB 176 >00</SUB 177 ></TD 178 ><TD 179 >Y'<SUB 180 >01</SUB 181 ></TD 182 ><TD 183 >Y'<SUB 184 >02</SUB 185 ></TD 186 ><TD 187 >Y'<SUB 188 >03</SUB 189 ></TD 190 ></TR 191 ><TR 192 ><TD 193 >start + 4:</TD 194 ><TD 195 >Y'<SUB 196 >10</SUB 197 ></TD 198 ><TD 199 >Y'<SUB 200 >11</SUB 201 ></TD 202 ><TD 203 >Y'<SUB 204 >12</SUB 205 ></TD 206 ><TD 207 >Y'<SUB 208 >13</SUB 209 ></TD 210 ></TR 211 ><TR 212 ><TD 213 >start + 8:</TD 214 ><TD 215 >Y'<SUB 216 >20</SUB 217 ></TD 218 ><TD 219 >Y'<SUB 220 >21</SUB 221 ></TD 222 ><TD 223 >Y'<SUB 224 >22</SUB 225 ></TD 226 ><TD 227 >Y'<SUB 228 >23</SUB 229 ></TD 230 ></TR 231 ><TR 232 ><TD 233 >start + 12:</TD 234 ><TD 235 >Y'<SUB 236 >30</SUB 237 ></TD 238 ><TD 239 >Y'<SUB 240 >31</SUB 241 ></TD 242 ><TD 243 >Y'<SUB 244 >32</SUB 245 ></TD 246 ><TD 247 >Y'<SUB 248 >33</SUB 249 ></TD 250 ></TR 251 ><TR 252 ><TD 253 >start + 16:</TD 254 ><TD 255 >Cb<SUB 256 >00</SUB 257 ></TD 258 ><TD 259 >Cr<SUB 260 >00</SUB 261 ></TD 262 ><TD 263 >Cb<SUB 264 >01</SUB 265 ></TD 266 ><TD 267 >Cr<SUB 268 >01</SUB 269 ></TD 270 ></TR 271 ><TR 272 ><TD 273 >start + 20:</TD 274 ><TD 275 >Cb<SUB 276 >10</SUB 277 ></TD 278 ><TD 279 >Cr<SUB 280 >10</SUB 281 ></TD 282 ><TD 283 >Cb<SUB 284 >11</SUB 285 ></TD 286 ><TD 287 >Cr<SUB 288 >11</SUB 289 ></TD 290 ></TR 291 ></TBODY 292 ></TABLE 293 ><P 294 ></P 295 ></DIV 296 > 297 </P 298 ></DIV 299 ><DIV 300 CLASS="FORMALPARA" 301 ><P 302 ><B 303 >Color Sample Location. </B 304 > <DIV 305 CLASS="INFORMALTABLE" 306 ><P 307 ></P 308 ><A 309 NAME="AEN5566" 310 ></A 311 ><TABLE 312 BORDER="0" 313 FRAME="void" 314 CLASS="CALSTABLE" 315 ><COL><COL><COL><COL><COL><COL><COL><TBODY 316 VALIGN="TOP" 317 ><TR 318 ><TD 319 > </TD 320 ><TD 321 >0</TD 322 ><TD 323 > </TD 324 ><TD 325 >1</TD 326 ><TD 327 > </TD 328 ><TD 329 >2</TD 330 ><TD 331 > </TD 332 ><TD 333 >3</TD 334 ></TR 335 ><TR 336 ><TD 337 >0</TD 338 ><TD 339 >Y</TD 340 ><TD 341 > </TD 342 ><TD 343 >Y</TD 344 ><TD 345 > </TD 346 ><TD 347 >Y</TD 348 ><TD 349 > </TD 350 ><TD 351 >Y</TD 352 ></TR 353 ><TR 354 ><TD 355 > </TD 356 ><TD 357 > </TD 358 ><TD 359 >C</TD 360 ><TD 361 > </TD 362 ><TD 363 > </TD 364 ><TD 365 > </TD 366 ><TD 367 >C</TD 368 ><TD 369 > </TD 370 ></TR 371 ><TR 372 ><TD 373 >1</TD 374 ><TD 375 >Y</TD 376 ><TD 377 > </TD 378 ><TD 379 >Y</TD 380 ><TD 381 > </TD 382 ><TD 383 >Y</TD 384 ><TD 385 > </TD 386 ><TD 387 >Y</TD 388 ></TR 389 ><TR 390 ><TD 391 > </TD 392 ><TD 393 > </TD 394 ><TD 395 > </TD 396 ><TD 397 > </TD 398 ><TD 399 > </TD 400 ><TD 401 > </TD 402 ><TD 403 > </TD 404 ></TR 405 ><TR 406 ><TD 407 >2</TD 408 ><TD 409 >Y</TD 410 ><TD 411 > </TD 412 ><TD 413 >Y</TD 414 ><TD 415 > </TD 416 ><TD 417 >Y</TD 418 ><TD 419 > </TD 420 ><TD 421 >Y</TD 422 ></TR 423 ><TR 424 ><TD 425 > </TD 426 ><TD 427 > </TD 428 ><TD 429 >C</TD 430 ><TD 431 > </TD 432 ><TD 433 > </TD 434 ><TD 435 > </TD 436 ><TD 437 >C</TD 438 ><TD 439 > </TD 440 ></TR 441 ><TR 442 ><TD 443 >3</TD 444 ><TD 445 >Y</TD 446 ><TD 447 > </TD 448 ><TD 449 >Y</TD 450 ><TD 451 > </TD 452 ><TD 453 >Y</TD 454 ><TD 455 > </TD 456 ><TD 457 >Y</TD 458 ></TR 459 ></TBODY 460 ></TABLE 461 ><P 462 ></P 463 ></DIV 464 > 465 </P 466 ></DIV 467 ></DIV 468 ></DIV 469 ><DIV 470 CLASS="NAVFOOTER" 471 ><HR 472 ALIGN="LEFT" 473 WIDTH="100%"><TABLE 474 SUMMARY="Footer navigation table" 475 WIDTH="100%" 476 BORDER="0" 477 CELLPADDING="0" 478 CELLSPACING="0" 479 ><TR 480 ><TD 481 WIDTH="33%" 482 ALIGN="left" 483 VALIGN="top" 484 ><A 485 HREF="r5319.htm" 486 ACCESSKEY="P" 487 >Prev</A 488 ></TD 489 ><TD 490 WIDTH="34%" 491 ALIGN="center" 492 VALIGN="top" 493 ><A 494 HREF="book1.htm" 495 ACCESSKEY="H" 496 >Home</A 497 ></TD 498 ><TD 499 WIDTH="33%" 500 ALIGN="right" 501 VALIGN="top" 502 ><A 503 HREF="x5634.htm" 504 ACCESSKEY="N" 505 >Next</A 506 ></TD 507 ></TR 508 ><TR 509 ><TD 510 WIDTH="33%" 511 ALIGN="left" 512 VALIGN="top" 513 >V4L2_PIX_FMT_YUV411P ('411P')</TD 514 ><TD 515 WIDTH="34%" 516 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