1    <refentry id="V4L2-PIX-FMT-YUV411P">
2      <refmeta>
3	<refentrytitle>V4L2_PIX_FMT_YUV411P ('411P')</refentrytitle>
4	&manvol;
5      </refmeta>
6      <refnamediv>
7	<refname><constant>V4L2_PIX_FMT_YUV411P</constant></refname>
8	<refpurpose>Format with &frac14; horizontal chroma resolution,
9also known as YUV 4:1:1. Planar layout as opposed to
10<constant>V4L2_PIX_FMT_Y41P</constant></refpurpose>
11      </refnamediv>
12      <refsect1>
13	<title>Description</title>
14
15	<para>This format is not commonly used. This is a planar
16format similar to the 4:2:2 planar format except with half as many
17chroma. The three components are separated into three sub-images or
18planes. The Y plane is first. The Y plane has one byte per pixel. The
19Cb plane immediately follows the Y plane in memory. The Cb plane is
20&frac14; the width of the Y plane (and of the image). Each Cb belongs
21to 4 pixels all on the same row. For example,
22Cb<subscript>0</subscript> belongs to Y'<subscript>00</subscript>,
23Y'<subscript>01</subscript>, Y'<subscript>02</subscript> and
24Y'<subscript>03</subscript>. Following the Cb plane is the Cr plane,
25just like the Cb plane.</para>
26
27	<para>If the Y plane has pad bytes after each row, then the Cr
28and Cb planes have &frac14; as many pad bytes after their rows. In
29other words, four C x rows (including padding) is exactly as long as
30one Y row (including padding).</para>
31
32	<example>
33	  <title><constant>V4L2_PIX_FMT_YUV411P</constant> 4 &times; 4
34pixel image</title>
35
36	  <formalpara>
37	    <title>Byte Order.</title>
38	    <para>Each cell is one byte.
39		<informaltable frame="none">
40		<tgroup cols="5" align="center">
41		  <colspec align="left" colwidth="2*" />
42		  <tbody valign="top">
43		    <row>
44		      <entry>start&nbsp;+&nbsp;0:</entry>
45		      <entry>Y'<subscript>00</subscript></entry>
46		      <entry>Y'<subscript>01</subscript></entry>
47		      <entry>Y'<subscript>02</subscript></entry>
48		      <entry>Y'<subscript>03</subscript></entry>
49		    </row>
50		    <row>
51		      <entry>start&nbsp;+&nbsp;4:</entry>
52		      <entry>Y'<subscript>10</subscript></entry>
53		      <entry>Y'<subscript>11</subscript></entry>
54		      <entry>Y'<subscript>12</subscript></entry>
55		      <entry>Y'<subscript>13</subscript></entry>
56		    </row>
57		    <row>
58		      <entry>start&nbsp;+&nbsp;8:</entry>
59		      <entry>Y'<subscript>20</subscript></entry>
60		      <entry>Y'<subscript>21</subscript></entry>
61		      <entry>Y'<subscript>22</subscript></entry>
62		      <entry>Y'<subscript>23</subscript></entry>
63		    </row>
64		    <row>
65		      <entry>start&nbsp;+&nbsp;12:</entry>
66		      <entry>Y'<subscript>30</subscript></entry>
67		      <entry>Y'<subscript>31</subscript></entry>
68		      <entry>Y'<subscript>32</subscript></entry>
69		      <entry>Y'<subscript>33</subscript></entry>
70		    </row>
71		    <row>
72		      <entry>start&nbsp;+&nbsp;16:</entry>
73		      <entry>Cb<subscript>00</subscript></entry>
74		    </row>
75		    <row>
76		      <entry>start&nbsp;+&nbsp;17:</entry>
77		      <entry>Cb<subscript>10</subscript></entry>
78		    </row>
79		    <row>
80		      <entry>start&nbsp;+&nbsp;18:</entry>
81		      <entry>Cb<subscript>20</subscript></entry>
82		    </row>
83		    <row>
84		      <entry>start&nbsp;+&nbsp;19:</entry>
85		      <entry>Cb<subscript>30</subscript></entry>
86		    </row>
87		    <row>
88		      <entry>start&nbsp;+&nbsp;20:</entry>
89		      <entry>Cr<subscript>00</subscript></entry>
90		    </row>
91		    <row>
92		      <entry>start&nbsp;+&nbsp;21:</entry>
93		      <entry>Cr<subscript>10</subscript></entry>
94		    </row>
95		    <row>
96		      <entry>start&nbsp;+&nbsp;22:</entry>
97		      <entry>Cr<subscript>20</subscript></entry>
98		    </row>
99		    <row>
100		      <entry>start&nbsp;+&nbsp;23:</entry>
101		      <entry>Cr<subscript>30</subscript></entry>
102		    </row>
103		  </tbody>
104		</tgroup>
105		</informaltable>
106	      </para>
107	  </formalpara>
108
109	  <formalpara>
110	    <title>Color Sample Location.</title>
111	    <para>
112		<informaltable frame="none">
113		<tgroup cols="7" align="center">
114		  <tbody valign="top">
115		    <row>
116		      <entry></entry>
117		      <entry>0</entry><entry></entry><entry>1</entry><entry></entry>
118		      <entry>2</entry><entry></entry><entry>3</entry>
119		    </row>
120		    <row>
121		      <entry>0</entry>
122		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
123		      <entry>Y</entry><entry></entry><entry>Y</entry>
124		    </row>
125		    <row>
126		      <entry>1</entry>
127		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
128		      <entry>Y</entry><entry></entry><entry>Y</entry>
129		    </row>
130		    <row>
131		      <entry>2</entry>
132		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
133		      <entry>Y</entry><entry></entry><entry>Y</entry>
134		    </row>
135		    <row>
136		      <entry>3</entry>
137		      <entry>Y</entry><entry></entry><entry>Y</entry><entry>C</entry>
138		      <entry>Y</entry><entry></entry><entry>Y</entry>
139		    </row>
140		  </tbody>
141		</tgroup>
142		</informaltable>
143	      </para>
144	  </formalpara>
145	</example>
146      </refsect1>
147    </refentry>
148