Documentation/DocBook/v4l/pixfmt-yuyv.xml

   1     <refentry id="V4L2-PIX-FMT-YUYV">
   2       <refmeta>
   3         <refentrytitle>V4L2_PIX_FMT_YUYV ('YUYV')</refentrytitle>
   4         &manvol;
   5       </refmeta>
   6       <refnamediv>
   7         <refname><constant>V4L2_PIX_FMT_YUYV</constant></refname>
   8         <refpurpose>Packed format with &frac12; horizontal chroma
   9 resolution, also known as YUV 4:2:2</refpurpose>
  10       </refnamediv>
  11       <refsect1>
  12         <title>Description</title>
  13
  14         <para>In this format each four bytes is two pixels. Each four
  15 bytes is two Y's, a Cb and a Cr. Each Y goes to one of the pixels, and
  16 the Cb and Cr belong to both pixels. As you can see, the Cr and Cb
  17 components have half the horizontal resolution of the Y component.
  18 <constant>V4L2_PIX_FMT_YUYV </constant> is known in the Windows
  19 environment as YUY2.</para>
  20
  21         <example>
  22           <title><constant>V4L2_PIX_FMT_YUYV</constant> 4 &times; 4
  23 pixel image</title>
  24
  25           <formalpara>
  26             <title>Byte Order.</title>
  27             <para>Each cell is one byte.
  28                 <informaltable frame="none">
  29                 <tgroup cols="9" align="center">
  30                   <colspec align="left" colwidth="2*" />
  31                   <tbody valign="top">
  32                     <row>
  33                       <entry>start&nbsp;+&nbsp;0:</entry>
  34                       <entry>Y'<subscript>00</subscript></entry>
  35                       <entry>Cb<subscript>00</subscript></entry>
  36                       <entry>Y'<subscript>01</subscript></entry>
  37                       <entry>Cr<subscript>00</subscript></entry>
  38                       <entry>Y'<subscript>02</subscript></entry>
  39                       <entry>Cb<subscript>01</subscript></entry>
  40                       <entry>Y'<subscript>03</subscript></entry>
  41                       <entry>Cr<subscript>01</subscript></entry>
  42                     </row>
  43                     <row>
  44                       <entry>start&nbsp;+&nbsp;8:</entry>
  45                       <entry>Y'<subscript>10</subscript></entry>
  46                       <entry>Cb<subscript>10</subscript></entry>
  47                       <entry>Y'<subscript>11</subscript></entry>
  48                       <entry>Cr<subscript>10</subscript></entry>
  49                       <entry>Y'<subscript>12</subscript></entry>
  50                       <entry>Cb<subscript>11</subscript></entry>
  51                       <entry>Y'<subscript>13</subscript></entry>
  52                       <entry>Cr<subscript>11</subscript></entry>
  53                     </row>
  54                     <row>
  55                       <entry>start&nbsp;+&nbsp;16:</entry>
  56                       <entry>Y'<subscript>20</subscript></entry>
  57                       <entry>Cb<subscript>20</subscript></entry>
  58                       <entry>Y'<subscript>21</subscript></entry>
  59                       <entry>Cr<subscript>20</subscript></entry>
  60                       <entry>Y'<subscript>22</subscript></entry>
  61                       <entry>Cb<subscript>21</subscript></entry>
  62                       <entry>Y'<subscript>23</subscript></entry>
  63                       <entry>Cr<subscript>21</subscript></entry>
  64                     </row>
  65                     <row>
  66                       <entry>start&nbsp;+&nbsp;24:</entry>
  67                       <entry>Y'<subscript>30</subscript></entry>
  68                       <entry>Cb<subscript>30</subscript></entry>
  69                       <entry>Y'<subscript>31</subscript></entry>
  70                       <entry>Cr<subscript>30</subscript></entry>
  71                       <entry>Y'<subscript>32</subscript></entry>
  72                       <entry>Cb<subscript>31</subscript></entry>
  73                       <entry>Y'<subscript>33</subscript></entry>
  74                       <entry>Cr<subscript>31</subscript></entry>
  75                     </row>
  76                   </tbody>
  77                 </tgroup>
  78                 </informaltable>
  79               </para>
  80           </formalpara>
  81
  82           <formalpara>
  83             <title>Color Sample Location.</title>
  84             <para>
  85                 <informaltable frame="none">
  86                 <tgroup cols="7" align="center">
  87                   <tbody valign="top">
  88                     <row>
  89                       <entry></entry>
  90                       <entry>0</entry><entry></entry><entry>1</entry><entry></entry>
  91                       <entry>2</entry><entry></entry><entry>3</entry>
  92                     </row>
  93                     <row>
  94                       <entry>0</entry>
  95                       <entry>Y</entry><entry>C</entry><entry>Y</entry><entry></entry>
  96                       <entry>Y</entry><entry>C</entry><entry>Y</entry>
  97                     </row>
  98                     <row>
  99                       <entry>1</entry>
 100                       <entry>Y</entry><entry>C</entry><entry>Y</entry><entry></entry>
 101                       <entry>Y</entry><entry>C</entry><entry>Y</entry>
 102                     </row>
 103                     <row>
 104                       <entry>2</entry>
 105                       <entry>Y</entry><entry>C</entry><entry>Y</entry><entry></entry>
 106                       <entry>Y</entry><entry>C</entry><entry>Y</entry>
 107                     </row>
 108                     <row>
 109                       <entry>3</entry>
 110                       <entry>Y</entry><entry>C</entry><entry>Y</entry><entry></entry>
 111                       <entry>Y</entry><entry>C</entry><entry>Y</entry>
 112                     </row>
 113                   </tbody>
 114                 </tgroup>
 115                 </informaltable>
 116               </para>
 117           </formalpara>
 118         </example>
 119       </refsect1>
 120     </refentry>
 121
 122   <!--
 123 Local Variables:
 124 mode: sgml
 125 sgml-parent-document: "pixfmt.sgml"
 126 indent-tabs-mode: nil
 127 End:
 128   -->