<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API" /><link rel="up" href="ch02s05.html" title="YUV Formats" /><link rel="prev" href="re13.html" title="V4L2_PIX_FMT_Y41P ('Y41P')" /><link rel="next" href="re15.html" title="V4L2_PIX_FMT_YVU410 ('YVU9'), V4L2_PIX_FMT_YUV410 ('YUV9')" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re13.html">Prev</a> </td><th width="60%" align="center">YUV Formats</th><td width="20%" align="right"> <a accesskey="n" href="re15.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')"><a id="id2622674"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p><code class="constant">V4L2_PIX_FMT_YVU420</code>, <code class="constant">V4L2_PIX_FMT_YUV420</code> — Planar formats with ½ horizontal and
vertical chroma resolution, also known as YUV 4:2:0</p></div><div class="refsect1" title="Description"><a id="id2622064"></a><h2>Description</h2><p>These are planar formats, as opposed to a packed format.
The three components are separated into three sub- images or planes.
The Y plane is first. The Y plane has one byte per pixel. For
<code class="constant">V4L2_PIX_FMT_YVU420</code>, the Cr plane immediately
follows the Y plane in memory. The Cr plane is half the width and half
the height of the Y plane (and of the image). Each Cr belongs to four
pixels, a two-by-two square of the image. For example,
Cr<sub>0</sub> belongs to Y'<sub>00</sub>,
Y'<sub>01</sub>, Y'<sub>10</sub>, and
Y'<sub>11</sub>. Following the Cr plane is the Cb plane,
just like the Cr plane. <code class="constant">V4L2_PIX_FMT_YUV420</code> is
the same except the Cb plane comes first, then the Cr plane.</p><p>If the Y plane has pad bytes after each row, then the Cr
and Cb planes have half as many pad bytes after their rows. In other
words, two Cx rows (including padding) is exactly as long as one Y row
(including padding).</p><div class="example"><a id="id2622724"></a><p class="title"><b>Example 2.14. <code class="constant">V4L2_PIX_FMT_YVU420</code> 4 × 4
pixel image</b></p><div class="example-contents"><p title="Byte Order."><b>Byte Order. </b>Each cell is one byte.
</p><div class="informaltable"><table border="0"><colgroup><col align="left" /><col /><col /><col /><col /></colgroup><tbody valign="top"><tr><td align="left" valign="top">start + 0:</td><td align="center" valign="top">Y'<sub>00</sub></td><td align="center" valign="top">Y'<sub>01</sub></td><td align="center" valign="top">Y'<sub>02</sub></td><td align="center" valign="top">Y'<sub>03</sub></td></tr><tr><td align="left" valign="top">start + 4:</td><td align="center" valign="top">Y'<sub>10</sub></td><td align="center" valign="top">Y'<sub>11</sub></td><td align="center" valign="top">Y'<sub>12</sub></td><td align="center" valign="top">Y'<sub>13</sub></td></tr><tr><td align="left" valign="top">start + 8:</td><td align="center" valign="top">Y'<sub>20</sub></td><td align="center" valign="top">Y'<sub>21</sub></td><td align="center" valign="top">Y'<sub>22</sub></td><td align="center" valign="top">Y'<sub>23</sub></td></tr><tr><td align="left" valign="top">start + 12:</td><td align="center" valign="top">Y'<sub>30</sub></td><td align="center" valign="top">Y'<sub>31</sub></td><td align="center" valign="top">Y'<sub>32</sub></td><td align="center" valign="top">Y'<sub>33</sub></td></tr><tr><td align="left" valign="top">start + 16:</td><td align="center" valign="top">Cr<sub>00</sub></td><td align="center" valign="top">Cr<sub>01</sub></td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr><tr><td align="left" valign="top">start + 18:</td><td align="center" valign="top">Cr<sub>10</sub></td><td align="center" valign="top">Cr<sub>11</sub></td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr><tr><td align="left" valign="top">start + 20:</td><td align="center" valign="top">Cb<sub>00</sub></td><td align="center" valign="top">Cb<sub>01</sub></td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr><tr><td align="left" valign="top">start + 22:</td><td align="center" valign="top">Cb<sub>10</sub></td><td align="center" valign="top">Cb<sub>11</sub></td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr></tbody></table></div><p title="Byte Order.">
</p><p title="Color Sample Location."><b>Color Sample Location. </b>
</p><div class="informaltable"><table border="0"><colgroup><col /><col /><col /><col /><col /><col /><col /></colgroup><tbody valign="top"><tr><td align="center" valign="top"> </td><td align="center" valign="top">0</td><td align="center" valign="top"> </td><td align="center" valign="top">1</td><td align="center" valign="top"> </td><td align="center" valign="top">2</td><td align="center" valign="top"> </td><td align="center" valign="top">3</td></tr><tr><td align="center" valign="top">0</td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td></tr><tr><td align="center" valign="top"> </td><td align="center" valign="top"> </td><td align="center" valign="top">C</td><td align="center" valign="top"> </td><td align="center" valign="top"> </td><td align="center" valign="top"> </td><td align="center" valign="top">C</td><td align="center" valign="top"> </td></tr><tr><td align="center" valign="top">1</td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td></tr><tr><td align="center" valign="top"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr><tr><td align="center" valign="top">2</td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td></tr><tr><td align="center" valign="top"> </td><td align="center" valign="top"> </td><td align="center" valign="top">C</td><td align="center" valign="top"> </td><td align="center" valign="top"> </td><td align="center" valign="top"> </td><td align="center" valign="top">C</td><td align="center" valign="top"> </td></tr><tr><td align="center" valign="top">3</td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td><td align="center" valign="top"> </td><td align="center" valign="top">Y</td></tr></tbody></table></div><p title="Color Sample Location.">
</p></div></div><br class="example-break" /></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re13.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch02s05.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re15.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">V4L2_PIX_FMT_Y41P ('Y41P') </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> V4L2_PIX_FMT_YVU410 ('YVU9'), V4L2_PIX_FMT_YUV410 ('YUV9')</td></tr></table></div></body></html>
