Documentation/DocBook/v4l/pixfmt-yuv410.xml

   1     <refentry>
   2       <refmeta>
   3         <refentrytitle>V4L2_PIX_FMT_YVU410 ('YVU9'), V4L2_PIX_FMT_YUV410 ('YUV9')</refentrytitle>
   4         &manvol;
   5       </refmeta>
   6       <refnamediv>
   7         <refname id="V4L2-PIX-FMT-YVU410"><constant>V4L2_PIX_FMT_YVU410</constant></refname>
   8         <refname id="V4L2-PIX-FMT-YUV410"><constant>V4L2_PIX_FMT_YUV410</constant></refname>
   9         <refpurpose>Planar formats with &frac14; horizontal and
  10 vertical chroma resolution, also known as YUV 4:1:0</refpurpose>
  11       </refnamediv>
  12       <refsect1>
  13         <title>Description</title>
  14
  15         <para>These are planar formats, as opposed to a packed format.
  16 The three components are separated into three sub-images or planes.
  17 The Y plane is first. The Y plane has one byte per pixel. For
  18 <constant>V4L2_PIX_FMT_YVU410</constant>, the Cr plane immediately
  19 follows the Y plane in memory. The Cr plane is &frac14; the width and
  20 &frac14; the height of the Y plane (and of the image). Each Cr belongs
  21 to 16 pixels, a four-by-four square of the image. Following the Cr
  22 plane is the Cb plane, just like the Cr plane.
  23 <constant>V4L2_PIX_FMT_YUV410</constant> is the same, except the Cb
  24 plane comes first, then the Cr plane.</para>
  25
  26         <para>If the Y plane has pad bytes after each row, then the Cr
  27 and Cb planes have &frac14; as many pad bytes after their rows. In
  28 other words, four Cx rows (including padding) are exactly as long as
  29 one Y row (including padding).</para>
  30
  31         <example>
  32           <title><constant>V4L2_PIX_FMT_YVU410</constant> 4 &times; 4
  33 pixel image</title>
  34
  35           <formalpara>
  36             <title>Byte Order.</title>
  37             <para>Each cell is one byte.
  38                 <informaltable frame="none">
  39                 <tgroup cols="5" align="center">
  40                   <colspec align="left" colwidth="2*" />
  41                   <tbody valign="top">
  42                     <row>
  43                       <entry>start&nbsp;+&nbsp;0:</entry>
  44                       <entry>Y'<subscript>00</subscript></entry>
  45                       <entry>Y'<subscript>01</subscript></entry>
  46                       <entry>Y'<subscript>02</subscript></entry>
  47                       <entry>Y'<subscript>03</subscript></entry>
  48                     </row>
  49                     <row>
  50                       <entry>start&nbsp;+&nbsp;4:</entry>
  51                       <entry>Y'<subscript>10</subscript></entry>
  52                       <entry>Y'<subscript>11</subscript></entry>
  53                       <entry>Y'<subscript>12</subscript></entry>
  54                       <entry>Y'<subscript>13</subscript></entry>
  55                     </row>
  56                     <row>
  57                       <entry>start&nbsp;+&nbsp;8:</entry>
  58                       <entry>Y'<subscript>20</subscript></entry>
  59                       <entry>Y'<subscript>21</subscript></entry>
  60                       <entry>Y'<subscript>22</subscript></entry>
  61                       <entry>Y'<subscript>23</subscript></entry>
  62                     </row>
  63                     <row>
  64                       <entry>start&nbsp;+&nbsp;12:</entry>
  65                       <entry>Y'<subscript>30</subscript></entry>
  66                       <entry>Y'<subscript>31</subscript></entry>
  67                       <entry>Y'<subscript>32</subscript></entry>
  68                       <entry>Y'<subscript>33</subscript></entry>
  69                     </row>
  70                     <row>
  71                       <entry>start&nbsp;+&nbsp;16:</entry>
  72                       <entry>Cr<subscript>00</subscript></entry>
  73                     </row>
  74                     <row>
  75                       <entry>start&nbsp;+&nbsp;17:</entry>
  76                       <entry>Cb<subscript>00</subscript></entry>
  77                     </row>
  78                   </tbody>
  79                 </tgroup>
  80                 </informaltable>
  81               </para>
  82           </formalpara>
  83
  84           <formalpara>
  85             <title>Color Sample Location.</title>
  86             <para>
  87                 <informaltable frame="none">
  88                 <tgroup cols="7" align="center">
  89                   <tbody valign="top">
  90                     <row>
  91                       <entry></entry>
  92                       <entry>0</entry><entry></entry><entry>1</entry><entry></entry>
  93                       <entry>2</entry><entry></entry><entry>3</entry>
  94                     </row>
  95                     <row>
  96                       <entry>0</entry>
  97                       <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
  98                       <entry>Y</entry><entry></entry><entry>Y</entry>
  99                     </row>
 100                     <row>
 101                       <entry></entry>
 102                     </row>
 103                     <row>
 104                       <entry>1</entry>
 105                       <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
 106                       <entry>Y</entry><entry></entry><entry>Y</entry>
 107                     </row>
 108                     <row>
 109                       <entry></entry>
 110                       <entry></entry><entry></entry><entry></entry><entry>C</entry>
 111                       <entry></entry><entry></entry><entry></entry>
 112                     </row>
 113                     <row>
 114                       <entry>2</entry>
 115                       <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
 116                       <entry>Y</entry><entry></entry><entry>Y</entry>
 117                     </row>
 118                     <row>
 119                       <entry></entry>
 120                     </row>
 121                     <row>
 122                       <entry>3</entry>
 123                       <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
 124                       <entry>Y</entry><entry></entry><entry>Y</entry>
 125                     </row>
 126                   </tbody>
 127                 </tgroup>
 128                 </informaltable>
 129               </para>
 130           </formalpara>
 131         </example>
 132       </refsect1>
 133     </refentry>
 134
 135   <!--
 136 Local Variables:
 137 mode: sgml
 138 sgml-parent-document: "pixfmt.sgml"
 139 indent-tabs-mode: nil
 140 End:
 141   -->