Documentation/DocBook/media/v4l/pixfmt-nv24.xml

   1     <refentry>
   2       <refmeta>
   3         <refentrytitle>V4L2_PIX_FMT_NV24 ('NV24'), V4L2_PIX_FMT_NV42 ('NV42')</refentrytitle>
   4         &manvol;
   5       </refmeta>
   6       <refnamediv>
   7         <refname id="V4L2-PIX-FMT-NV24"><constant>V4L2_PIX_FMT_NV24</constant></refname>
   8         <refname id="V4L2-PIX-FMT-NV42"><constant>V4L2_PIX_FMT_NV42</constant></refname>
   9         <refpurpose>Formats with full horizontal and vertical
  10 chroma resolutions, also known as YUV 4:4:4. One luminance and one
  11 chrominance plane with alternating chroma samples as opposed to
  12 <constant>V4L2_PIX_FMT_YVU420</constant></refpurpose>
  13       </refnamediv>
  14       <refsect1>
  15         <title>Description</title>
  16
  17         <para>These are two-plane versions of the YUV 4:4:4 format. The three
  18         components are separated into two sub-images or planes. The Y plane is
  19         first, with each Y sample stored in one byte per pixel. For
  20         <constant>V4L2_PIX_FMT_NV24</constant>, a combined CbCr plane
  21         immediately follows the Y plane in memory. The CbCr plane has the same
  22         width and height, in pixels, as the Y plane (and the image). Each line
  23         contains one CbCr pair per pixel, with each Cb and Cr sample stored in
  24         one byte. <constant>V4L2_PIX_FMT_NV42</constant> is the same except that
  25         the Cb and Cr samples are swapped, the CrCb plane starts with a Cr
  26         sample.</para>
  27
  28         <para>If the Y plane has pad bytes after each row, then the CbCr plane
  29         has twice as many pad bytes after its rows.</para>
  30
  31         <example>
  32           <title><constant>V4L2_PIX_FMT_NV24</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="9" 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>Cb<subscript>00</subscript></entry>
  73                       <entry>Cr<subscript>00</subscript></entry>
  74                       <entry>Cb<subscript>01</subscript></entry>
  75                       <entry>Cr<subscript>01</subscript></entry>
  76                       <entry>Cb<subscript>02</subscript></entry>
  77                       <entry>Cr<subscript>02</subscript></entry>
  78                       <entry>Cb<subscript>03</subscript></entry>
  79                       <entry>Cr<subscript>03</subscript></entry>
  80                     </row>
  81                     <row>
  82                       <entry>start&nbsp;+&nbsp;24:</entry>
  83                       <entry>Cb<subscript>10</subscript></entry>
  84                       <entry>Cr<subscript>10</subscript></entry>
  85                       <entry>Cb<subscript>11</subscript></entry>
  86                       <entry>Cr<subscript>11</subscript></entry>
  87                       <entry>Cb<subscript>12</subscript></entry>
  88                       <entry>Cr<subscript>12</subscript></entry>
  89                       <entry>Cb<subscript>13</subscript></entry>
  90                       <entry>Cr<subscript>13</subscript></entry>
  91                     </row>
  92                     <row>
  93                       <entry>start&nbsp;+&nbsp;32:</entry>
  94                       <entry>Cb<subscript>20</subscript></entry>
  95                       <entry>Cr<subscript>20</subscript></entry>
  96                       <entry>Cb<subscript>21</subscript></entry>
  97                       <entry>Cr<subscript>21</subscript></entry>
  98                       <entry>Cb<subscript>22</subscript></entry>
  99                       <entry>Cr<subscript>22</subscript></entry>
 100                       <entry>Cb<subscript>23</subscript></entry>
 101                       <entry>Cr<subscript>23</subscript></entry>
 102                     </row>
 103                     <row>
 104                       <entry>start&nbsp;+&nbsp;40:</entry>
 105                       <entry>Cb<subscript>30</subscript></entry>
 106                       <entry>Cr<subscript>30</subscript></entry>
 107                       <entry>Cb<subscript>31</subscript></entry>
 108                       <entry>Cr<subscript>31</subscript></entry>
 109                       <entry>Cb<subscript>32</subscript></entry>
 110                       <entry>Cr<subscript>32</subscript></entry>
 111                       <entry>Cb<subscript>33</subscript></entry>
 112                       <entry>Cr<subscript>33</subscript></entry>
 113                     </row>
 114                   </tbody>
 115                 </tgroup>
 116                 </informaltable>
 117               </para>
 118           </formalpara>
 119         </example>
 120       </refsect1>
 121     </refentry>