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_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')</TITLE 6><META 7NAME="GENERATOR" 8CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK 9REL="HOME" 10TITLE="Video for Linux Two API Specification" 11HREF="book1.htm"><LINK 12REL="UP" 13TITLE="YUV Formats" 14HREF="x3891.htm"><LINK 15REL="PREVIOUS" 16TITLE="V4L2_PIX_FMT_Y41P ('Y41P')" 17HREF="r4629.htm"><LINK 18REL="NEXT" 19TITLE="V4L2_PIX_FMT_YVU410 ('YVU9'), V4L2_PIX_FMT_YUV410 ('YUV9')" 20HREF="r5016.htm"></HEAD 21><BODY 22CLASS="REFENTRY" 23BGCOLOR="#FFFFFF" 24TEXT="#000000" 25LINK="#0000FF" 26VLINK="#840084" 27ALINK="#0000FF" 28><DIV 29CLASS="NAVHEADER" 30><TABLE 31SUMMARY="Header navigation table" 32WIDTH="100%" 33BORDER="0" 34CELLPADDING="0" 35CELLSPACING="0" 36><TR 37><TH 38COLSPAN="3" 39ALIGN="center" 40>Video for Linux Two API Specification: Revision 0.24</TH 41></TR 42><TR 43><TD 44WIDTH="10%" 45ALIGN="left" 46VALIGN="bottom" 47><A 48HREF="r4629.htm" 49ACCESSKEY="P" 50>Prev</A 51></TD 52><TD 53WIDTH="80%" 54ALIGN="center" 55VALIGN="bottom" 56></TD 57><TD 58WIDTH="10%" 59ALIGN="right" 60VALIGN="bottom" 61><A 62HREF="r5016.htm" 63ACCESSKEY="N" 64>Next</A 65></TD 66></TR 67></TABLE 68><HR 69ALIGN="LEFT" 70WIDTH="100%"></DIV 71><H1 72><A 73NAME="AEN4850" 74></A 75>V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')</H1 76><DIV 77CLASS="REFNAMEDIV" 78><A 79NAME="AEN4854" 80></A 81><H2 82>Name</H2 83><CODE 84CLASS="CONSTANT" 85>V4L2_PIX_FMT_YVU420</CODE 86>, <CODE 87CLASS="CONSTANT" 88>V4L2_PIX_FMT_YUV420</CODE 89> -- Planar formats with ½ horizontal and 90vertical chroma resolution, also known as YUV 4:2:0</DIV 91><DIV 92CLASS="REFSECT1" 93><A 94NAME="AEN4860" 95></A 96><H2 97>Description</H2 98><P 99>These are planar formats, as opposed to a packed format. 100The three components are separated into three sub- images or planes. 101The Y plane is first. The Y plane has one byte per pixel. For 102<CODE 103CLASS="CONSTANT" 104>V4L2_PIX_FMT_YVU420</CODE 105>, the Cr plane immediately 106follows the Y plane in memory. The Cr plane is half the width and half 107the height of the Y plane (and of the image). Each Cr belongs to four 108pixels, a two-by-two square of the image. For example, 109Cr<SUB 110>0</SUB 111> belongs to Y'<SUB 112>00</SUB 113>, 114Y'<SUB 115>01</SUB 116>, Y'<SUB 117>10</SUB 118>, and 119Y'<SUB 120>11</SUB 121>. Following the Cr plane is the Cb plane, 122just like the Cr plane. <CODE 123CLASS="CONSTANT" 124>V4L2_PIX_FMT_YUV420</CODE 125> is 126the same except the Cb plane comes first, then the Cr plane.</P 127><P 128>If the Y plane has pad bytes after each row, then the Cr 129and Cb planes have half as many pad bytes after their rows. In other 130words, two Cx rows (including padding) is exactly as long as one Y row 131(including padding).</P 132><DIV 133CLASS="EXAMPLE" 134><A 135NAME="AEN4871" 136></A 137><P 138><B 139>Example 2-1. <CODE 140CLASS="CONSTANT" 141>V4L2_PIX_FMT_YVU420</CODE 142> 4 × 4 143pixel image</B 144></P 145><DIV 146CLASS="FORMALPARA" 147><P 148><B 149>Byte Order. </B 150>Each cell is one byte. 151 <DIV 152CLASS="INFORMALTABLE" 153><P 154></P 155><A 156NAME="AEN4877" 157></A 158><TABLE 159BORDER="0" 160FRAME="void" 161CLASS="CALSTABLE" 162><COL 163WIDTH="2*" 164ALIGN="LEFT"><COL><COL><COL><COL><TBODY 165VALIGN="TOP" 166><TR 167><TD 168>start + 0:</TD 169><TD 170>Y'<SUB 171>00</SUB 172></TD 173><TD 174>Y'<SUB 175>01</SUB 176></TD 177><TD 178>Y'<SUB 179>02</SUB 180></TD 181><TD 182>Y'<SUB 183>03</SUB 184></TD 185></TR 186><TR 187><TD 188>start + 4:</TD 189><TD 190>Y'<SUB 191>10</SUB 192></TD 193><TD 194>Y'<SUB 195>11</SUB 196></TD 197><TD 198>Y'<SUB 199>12</SUB 200></TD 201><TD 202>Y'<SUB 203>13</SUB 204></TD 205></TR 206><TR 207><TD 208>start + 8:</TD 209><TD 210>Y'<SUB 211>20</SUB 212></TD 213><TD 214>Y'<SUB 215>21</SUB 216></TD 217><TD 218>Y'<SUB 219>22</SUB 220></TD 221><TD 222>Y'<SUB 223>23</SUB 224></TD 225></TR 226><TR 227><TD 228>start + 12:</TD 229><TD 230>Y'<SUB 231>30</SUB 232></TD 233><TD 234>Y'<SUB 235>31</SUB 236></TD 237><TD 238>Y'<SUB 239>32</SUB 240></TD 241><TD 242>Y'<SUB 243>33</SUB 244></TD 245></TR 246><TR 247><TD 248>start + 16:</TD 249><TD 250>Cr<SUB 251>00</SUB 252></TD 253><TD 254>Cr<SUB 255>01</SUB 256></TD 257><TD 258> </TD 259><TD 260> </TD 261></TR 262><TR 263><TD 264>start + 18:</TD 265><TD 266>Cr<SUB 267>10</SUB 268></TD 269><TD 270>Cr<SUB 271>11</SUB 272></TD 273><TD 274> </TD 275><TD 276> </TD 277></TR 278><TR 279><TD 280>start + 20:</TD 281><TD 282>Cb<SUB 283>00</SUB 284></TD 285><TD 286>Cb<SUB 287>01</SUB 288></TD 289><TD 290> </TD 291><TD 292> </TD 293></TR 294><TR 295><TD 296>start + 22:</TD 297><TD 298>Cb<SUB 299>10</SUB 300></TD 301><TD 302>Cb<SUB 303>11</SUB 304></TD 305><TD 306> </TD 307><TD 308> </TD 309></TR 310></TBODY 311></TABLE 312><P 313></P 314></DIV 315> 316 </P 317></DIV 318><DIV 319CLASS="FORMALPARA" 320><P 321><B 322>Color Sample Location. </B 323> <DIV 324CLASS="INFORMALTABLE" 325><P 326></P 327><A 328NAME="AEN4948" 329></A 330><TABLE 331BORDER="0" 332FRAME="void" 333CLASS="CALSTABLE" 334><COL><COL><COL><COL><COL><COL><COL><TBODY 335VALIGN="TOP" 336><TR 337><TD 338> </TD 339><TD 340>0</TD 341><TD 342> </TD 343><TD 344>1</TD 345><TD 346> </TD 347><TD 348>2</TD 349><TD 350> </TD 351><TD 352>3</TD 353></TR 354><TR 355><TD 356>0</TD 357><TD 358>Y</TD 359><TD 360> </TD 361><TD 362>Y</TD 363><TD 364> </TD 365><TD 366>Y</TD 367><TD 368> </TD 369><TD 370>Y</TD 371></TR 372><TR 373><TD 374> </TD 375><TD 376> </TD 377><TD 378>C</TD 379><TD 380> </TD 381><TD 382> </TD 383><TD 384> </TD 385><TD 386>C</TD 387><TD 388> </TD 389></TR 390><TR 391><TD 392>1</TD 393><TD 394>Y</TD 395><TD 396> </TD 397><TD 398>Y</TD 399><TD 400> </TD 401><TD 402>Y</TD 403><TD 404> </TD 405><TD 406>Y</TD 407></TR 408><TR 409><TD 410> </TD 411><TD 412> </TD 413><TD 414> </TD 415><TD 416> </TD 417><TD 418> </TD 419><TD 420> </TD 421><TD 422> </TD 423></TR 424><TR 425><TD 426>2</TD 427><TD 428>Y</TD 429><TD 430> </TD 431><TD 432>Y</TD 433><TD 434> </TD 435><TD 436>Y</TD 437><TD 438> </TD 439><TD 440>Y</TD 441></TR 442><TR 443><TD 444> </TD 445><TD 446> </TD 447><TD 448>C</TD 449><TD 450> </TD 451><TD 452> </TD 453><TD 454> </TD 455><TD 456>C</TD 457><TD 458> </TD 459></TR 460><TR 461><TD 462>3</TD 463><TD 464>Y</TD 465><TD 466> </TD 467><TD 468>Y</TD 469><TD 470> </TD 471><TD 472>Y</TD 473><TD 474> </TD 475><TD 476>Y</TD 477></TR 478></TBODY 479></TABLE 480><P 481></P 482></DIV 483> 484 </P 485></DIV 486></DIV 487></DIV 488><DIV 489CLASS="NAVFOOTER" 490><HR 491ALIGN="LEFT" 492WIDTH="100%"><TABLE 493SUMMARY="Footer navigation table" 494WIDTH="100%" 495BORDER="0" 496CELLPADDING="0" 497CELLSPACING="0" 498><TR 499><TD 500WIDTH="33%" 501ALIGN="left" 502VALIGN="top" 503><A 504HREF="r4629.htm" 505ACCESSKEY="P" 506>Prev</A 507></TD 508><TD 509WIDTH="34%" 510ALIGN="center" 511VALIGN="top" 512><A 513HREF="book1.htm" 514ACCESSKEY="H" 515>Home</A 516></TD 517><TD 518WIDTH="33%" 519ALIGN="right" 520VALIGN="top" 521><A 522HREF="r5016.htm" 523ACCESSKEY="N" 524>Next</A 525></TD 526></TR 527><TR 528><TD 529WIDTH="33%" 530ALIGN="left" 531VALIGN="top" 532>V4L2_PIX_FMT_Y41P ('Y41P')</TD 533><TD 534WIDTH="34%" 535ALIGN="center" 536VALIGN="top" 537><A 538HREF="x3891.htm" 539ACCESSKEY="U" 540>Up</A 541></TD 542><TD 543WIDTH="33%" 544ALIGN="right" 545VALIGN="top" 546>V4L2_PIX_FMT_YVU410 ('YVU9'), V4L2_PIX_FMT_YUV410 ('YUV9')</TD 547></TR 548></TABLE 549></DIV 550></BODY 551></HTML 552> 553