Documentation/DocBook/media/v4l/pixfmt-y12i.xml


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<refentry id="V4L2-PIX-FMT-Y12I">
  <refmeta>
    <refentrytitle>V4L2_PIX_FMT_Y12I ('Y12I')</refentrytitle>
    &manvol;
  </refmeta>
  <refnamediv>
    <refname><constant>V4L2_PIX_FMT_Y12I</constant></refname>
    <refpurpose>Interleaved grey-scale image, e.g. from a stereo-pair</refpurpose>
  </refnamediv>
  <refsect1>
    <title>Description</title>

    <para>This is a grey-scale image with a depth of 12 bits per pixel, but with
pixels from 2 sources interleaved and bit-packed. Each pixel is stored in a
24-bit word in the little-endian order. On a little-endian machine these pixels
can be deinterlaced using</para>

<para>
<programlisting>
__u8 *buf;
left0 = 0xfff &amp; *(__u16 *)buf;
right0 = *(__u16 *)(buf + 1) >> 4;
</programlisting>
</para>

    <example>
      <title><constant>V4L2_PIX_FMT_Y12I</constant> 2 pixel data stream taking 3 bytes</title>

      <formalpara>
	<title>Bit-packed representation</title>
	<para>pixels cross the byte boundary and have a ratio of 3 bytes for each
          interleaved pixel.
	  <informaltable frame="all">
	    <tgroup cols="3" align="center">
	      <colspec align="left" colwidth="2*" />
	      <tbody valign="top">
		<row>
		  <entry>Y'<subscript>0left[7:0]</subscript></entry>
		  <entry>Y'<subscript>0right[3:0]</subscript>Y'<subscript>0left[11:8]</subscript></entry>
		  <entry>Y'<subscript>0right[11:4]</subscript></entry>
		</row>
	      </tbody>
	    </tgroup>
	  </informaltable>
	</para>
      </formalpara>
    </example>
  </refsect1>
</refentry>