path: root/Documentation/DocBook/v4l/pixfmt-y41p.xml

    <refentry id="V4L2-PIX-FMT-Y41P">
      <refmeta>
	<refentrytitle>V4L2_PIX_FMT_Y41P ('Y41P')</refentrytitle>
	&manvol;
      </refmeta>
      <refnamediv>
	<refname><constant>V4L2_PIX_FMT_Y41P</constant></refname>
	<refpurpose>Format with &frac14; horizontal chroma
resolution, also known as YUV 4:1:1</refpurpose>
      </refnamediv>
      <refsect1>
	<title>Description</title>

	<para>In this format each 12 bytes is eight pixels. In the
twelve bytes are two CbCr pairs and eight Y's. The first CbCr pair
goes with the first four Y's, and the second CbCr pair goes with the
other four Y's. The Cb and Cr components have one fourth the
horizontal resolution of the Y component.</para>

	<para>Do not confuse this format with <link
linkend="V4L2-PIX-FMT-YUV411P"><constant>V4L2_PIX_FMT_YUV411P</constant></link>.
Y41P is derived from "YUV 4:1:1 <emphasis>packed</emphasis>", while
YUV411P stands for "YUV 4:1:1 <emphasis>planar</emphasis>".</para>

	<example>
	  <title><constant>V4L2_PIX_FMT_Y41P</constant> 8 &times; 4
pixel image</title>

	  <formalpara>
	    <title>Byte Order</title>
	    <para>Each cell is one byte.
		<informaltable frame="none">
		<tgroup cols="13" align="center">
		  <colspec align="left" colwidth="2*" />
		  <tbody valign="top">
		    <row>
		      <entry>start&nbsp;+&nbsp;0:</entry>
		      <entry>Cb<subscript>00</subscript></entry>
		      <entry>Y'<subscript>00</subscript></entry>
		      <entry>Cr<subscript>00</subscript></entry>
		      <entry>Y'<subscript>01</subscript></entry>
		      <entry>Cb<subscript>01</subscript></entry>
		      <entry>Y'<subscript>02</subscript></entry>
		      <entry>Cr<subscript>01</subscript></entry>
		      <entry>Y'<subscript>03</subscript></entry>
		      <entry>Y'<subscript>04</subscript></entry>
		      <entry>Y'<subscript>05</subscript></entry>
		      <entry>Y'<subscript>06</subscript></entry>
		      <entry>Y'<subscript>07</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;12:</entry>
		      <entry>Cb<subscript>10</subscript></entry>
		      <entry>Y'<subscript>10</subscript></entry>
		      <entry>Cr<subscript>10</subscript></entry>
		      <entry>Y'<subscript>11</subscript></entry>
		      <entry>Cb<subscript>11</subscript></entry>
		      <entry>Y'<subscript>12</subscript></entry>
		      <entry>Cr<subscript>11</subscript></entry>
		      <entry>Y'<subscript>13</subscript></entry>
		      <entry>Y'<subscript>14</subscript></entry>
		      <entry>Y'<subscript>15</subscript></entry>
		      <entry>Y'<subscript>16</subscript></entry>
		      <entry>Y'<subscript>17</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;24:</entry>
		      <entry>Cb<subscript>20</subscript></entry>
		      <entry>Y'<subscript>20</subscript></entry>
		      <entry>Cr<subscript>20</subscript></entry>
		      <entry>Y'<subscript>21</subscript></entry>
		      <entry>Cb<subscript>21</subscript></entry>
		      <entry>Y'<subscript>22</subscript></entry>
		      <entry>Cr<subscript>21</subscript></entry>
		      <entry>Y'<subscript>23</subscript></entry>
		      <entry>Y'<subscript>24</subscript></entry>
		      <entry>Y'<subscript>25</subscript></entry>
		      <entry>Y'<subscript>26</subscript></entry>
		      <entry>Y'<subscript>27</subscript></entry>
		    </row>
		    <row>
		      <entry>start&nbsp;+&nbsp;36:</entry>
		      <entry>Cb<subscript>30</subscript></entry>
		      <entry>Y'<subscript>30</subscript></entry>
		      <entry>Cr<subscript>30</subscript></entry>
		      <entry>Y'<subscript>31</subscript></entry>
		      <entry>Cb<subscript>31</subscript></entry>
		      <entry>Y'<subscript>32</subscript></entry>
		      <entry>Cr<subscript>31</subscript></entry>
		      <entry>Y'<subscript>33</subscript></entry>
		      <entry>Y'<subscript>34</subscript></entry>
		      <entry>Y'<subscript>35</subscript></entry>
		      <entry>Y'<subscript>36</subscript></entry>
		      <entry>Y'<subscript>37</subscript></entry>
		    </row>
		  </tbody>
		</tgroup>
	      </informaltable></para>
	  </formalpara>

	  <formalpara>
	    <title>Color Sample Location.</title>
	    <para>
		<informaltable frame="none">
		<tgroup cols="15" align="center">
		  <tbody valign="top">
		    <row>
		      <entry></entry>
		      <entry>0</entry><entry></entry><entry>1</entry><entry></entry>
		      <entry>2</entry><entry></entry><entry>3</entry><entry></entry>
		      <entry>4</entry><entry></entry><entry>5</entry><entry></entry>
		      <entry>6</entry><entry></entry><entry>7</entry>
		    </row>
		    <row>
		      <entry>0</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		    <row>
		      <entry>1</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		    <row>
		      <entry>2</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		    <row>
		      <entry>3</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
		      <entry>Y</entry><entry></entry><entry>Y</entry>
		    </row>
		  </tbody>
		</tgroup>
		</informaltable>
	      </para>
	  </formalpara>
	</example>
      </refsect1>
    </refentry>

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