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authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-21 09:03:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-21 09:03:10 -0700
commitc720f5655df159a630fa0290a0bd67c93e92b0bf (patch)
tree940d139d0ec1ff5201efddef6cc663166a8a2df3 /Documentation/DocBook/v4l/pixfmt-yuv420.xml
parent33e6c1a0de818d3698cdab27c42915661011319d (diff)
parent84d6ae431f315e8973aac3c3fe1d550fc9240ef3 (diff)
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (222 commits) V4L/DVB (13033): pt1: Don't use a deprecated DMA_BIT_MASK macro V4L/DVB (13029): radio-si4713: remove #include <linux/version.h> V4L/DVB (13027): go7007: convert printks to v4l2_info V4L/DVB (13026): s2250-board: Implement brightness and contrast controls V4L/DVB (13025): s2250-board: Fix memory leaks V4L/DVB (13024): go7007: Implement vidioc_g_std and vidioc_querystd V4L/DVB (13023): go7007: Merge struct gofh and go declarations V4L/DVB (13022): go7007: Fix mpeg controls V4L/DVB (13021): go7007: Fix whitespace and line lengths V4L/DVB (13020): go7007: Updates to Kconfig and Makefile V4L/DVB (13019): video: initial support for ADV7180 V4L/DVB (13018): kzalloc failure ignored in au8522_probe() V4L/DVB (13017): gspca: kmalloc failure ignored in sd_start() V4L/DVB (13016): kmalloc failure ignored in lgdt3304_attach() and s921_attach() V4L/DVB (13015): kmalloc failure ignored in m920x_firmware_download() V4L/DVB (13014): Add support for Compro VideoMate E800 (DVB-T part only) V4L/DVB (13013): FM TX: si4713: Kconfig: Fixed two typos. V4L/DVB (13012): uvc: introduce missing kfree V4L/DVB (13011): Change tuner type of BeholdTV cards V4L/DVB (13009): gspca - stv06xx-hdcs: Reduce exposure range ...
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+ <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 &frac12; 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 &times; 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&nbsp;+&nbsp;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&nbsp;+&nbsp;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&nbsp;+&nbsp;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&nbsp;+&nbsp;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&nbsp;+&nbsp;16:</entry>
+ <entry>Cr<subscript>00</subscript></entry>
+ <entry>Cr<subscript>01</subscript></entry>
+ </row>
+ <row>
+ <entry>start&nbsp;+&nbsp;18:</entry>
+ <entry>Cr<subscript>10</subscript></entry>
+ <entry>Cr<subscript>11</subscript></entry>
+ </row>
+ <row>
+ <entry>start&nbsp;+&nbsp;20:</entry>
+ <entry>Cb<subscript>00</subscript></entry>
+ <entry>Cb<subscript>01</subscript></entry>
+ </row>
+ <row>
+ <entry>start&nbsp;+&nbsp;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>
+
+ <!--
+Local Variables:
+mode: sgml
+sgml-parent-document: "pixfmt.sgml"
+indent-tabs-mode: nil
+End:
+ -->