mirror of
https://github.com/torvalds/linux.git
synced 2024-12-16 16:12:52 +00:00
c6401af669
This removes comment tags intended for emacs configuration from 67 files in the Media API DocBook. Such comments are not really helpful and violate the coding style rules. Signed-off-by: Sylwester Nawrocki <snjw23@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
150 lines
5.2 KiB
XML
150 lines
5.2 KiB
XML
<refentry>
|
|
<refmeta>
|
|
<refentrytitle>V4L2_PIX_FMT_YVU420 ('YV12'), V4L2_PIX_FMT_YUV420 ('YU12')</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
<refnamediv>
|
|
<refname id="V4L2-PIX-FMT-YVU420"><constant>V4L2_PIX_FMT_YVU420</constant></refname>
|
|
<refname id="V4L2-PIX-FMT-YUV420"><constant>V4L2_PIX_FMT_YUV420</constant></refname>
|
|
<refpurpose>Planar formats with ½ horizontal and
|
|
vertical chroma resolution, also known as YUV 4:2:0</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>These are planar formats, as opposed to a packed format.
|
|
The three components are separated into three sub- images or planes.
|
|
The Y plane is first. The Y plane has one byte per pixel. For
|
|
<constant>V4L2_PIX_FMT_YVU420</constant>, the Cr plane immediately
|
|
follows the Y plane in memory. The Cr plane is half the width and half
|
|
the height of the Y plane (and of the image). Each Cr belongs to four
|
|
pixels, a two-by-two square of the image. For example,
|
|
Cr<subscript>0</subscript> belongs to Y'<subscript>00</subscript>,
|
|
Y'<subscript>01</subscript>, Y'<subscript>10</subscript>, and
|
|
Y'<subscript>11</subscript>. Following the Cr plane is the Cb plane,
|
|
just like the Cr plane. <constant>V4L2_PIX_FMT_YUV420</constant> is
|
|
the same except the Cb plane comes first, then the Cr plane.</para>
|
|
|
|
<para>If the Y plane has pad bytes after each row, then the Cr
|
|
and Cb planes have half as many pad bytes after their rows. In other
|
|
words, two Cx rows (including padding) is exactly as long as one Y row
|
|
(including padding).</para>
|
|
|
|
<example>
|
|
<title><constant>V4L2_PIX_FMT_YVU420</constant> 4 × 4
|
|
pixel image</title>
|
|
|
|
<formalpara>
|
|
<title>Byte Order.</title>
|
|
<para>Each cell is one byte.
|
|
<informaltable frame="none">
|
|
<tgroup cols="5" align="center">
|
|
<colspec align="left" colwidth="2*" />
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>start + 0:</entry>
|
|
<entry>Y'<subscript>00</subscript></entry>
|
|
<entry>Y'<subscript>01</subscript></entry>
|
|
<entry>Y'<subscript>02</subscript></entry>
|
|
<entry>Y'<subscript>03</subscript></entry>
|
|
</row>
|
|
<row>
|
|
<entry>start + 4:</entry>
|
|
<entry>Y'<subscript>10</subscript></entry>
|
|
<entry>Y'<subscript>11</subscript></entry>
|
|
<entry>Y'<subscript>12</subscript></entry>
|
|
<entry>Y'<subscript>13</subscript></entry>
|
|
</row>
|
|
<row>
|
|
<entry>start + 8:</entry>
|
|
<entry>Y'<subscript>20</subscript></entry>
|
|
<entry>Y'<subscript>21</subscript></entry>
|
|
<entry>Y'<subscript>22</subscript></entry>
|
|
<entry>Y'<subscript>23</subscript></entry>
|
|
</row>
|
|
<row>
|
|
<entry>start + 12:</entry>
|
|
<entry>Y'<subscript>30</subscript></entry>
|
|
<entry>Y'<subscript>31</subscript></entry>
|
|
<entry>Y'<subscript>32</subscript></entry>
|
|
<entry>Y'<subscript>33</subscript></entry>
|
|
</row>
|
|
<row>
|
|
<entry>start + 16:</entry>
|
|
<entry>Cr<subscript>00</subscript></entry>
|
|
<entry>Cr<subscript>01</subscript></entry>
|
|
</row>
|
|
<row>
|
|
<entry>start + 18:</entry>
|
|
<entry>Cr<subscript>10</subscript></entry>
|
|
<entry>Cr<subscript>11</subscript></entry>
|
|
</row>
|
|
<row>
|
|
<entry>start + 20:</entry>
|
|
<entry>Cb<subscript>00</subscript></entry>
|
|
<entry>Cb<subscript>01</subscript></entry>
|
|
</row>
|
|
<row>
|
|
<entry>start + 22:</entry>
|
|
<entry>Cb<subscript>10</subscript></entry>
|
|
<entry>Cb<subscript>11</subscript></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
</formalpara>
|
|
|
|
<formalpara>
|
|
<title>Color Sample Location.</title>
|
|
<para>
|
|
<informaltable frame="none">
|
|
<tgroup cols="7" align="center">
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry></entry>
|
|
<entry>0</entry><entry></entry><entry>1</entry><entry></entry>
|
|
<entry>2</entry><entry></entry><entry>3</entry>
|
|
</row>
|
|
<row>
|
|
<entry>0</entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry>
|
|
</row>
|
|
<row>
|
|
<entry></entry>
|
|
<entry></entry><entry>C</entry><entry></entry><entry></entry>
|
|
<entry></entry><entry>C</entry><entry></entry>
|
|
</row>
|
|
<row>
|
|
<entry>1</entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry>
|
|
</row>
|
|
<row>
|
|
<entry></entry>
|
|
</row>
|
|
<row>
|
|
<entry>2</entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry>
|
|
</row>
|
|
<row>
|
|
<entry></entry>
|
|
<entry></entry><entry>C</entry><entry></entry><entry></entry>
|
|
<entry></entry><entry>C</entry><entry></entry>
|
|
</row>
|
|
<row>
|
|
<entry>3</entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
|
|
<entry>Y</entry><entry></entry><entry>Y</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
</formalpara>
|
|
</example>
|
|
</refsect1>
|
|
</refentry>
|