aboutsummaryrefslogtreecommitdiff
path: root/Documentation/DocBook/media/v4l/pixfmt-yvu420m.xml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DocBook/media/v4l/pixfmt-yvu420m.xml')
-rw-r--r--Documentation/DocBook/media/v4l/pixfmt-yvu420m.xml154
1 files changed, 154 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/pixfmt-yvu420m.xml b/Documentation/DocBook/media/v4l/pixfmt-yvu420m.xml
new file mode 100644
index 00000000..23306679
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/pixfmt-yvu420m.xml
@@ -0,0 +1,154 @@
+ <refentry id="V4L2-PIX-FMT-YVU420M">
+ <refmeta>
+ <refentrytitle>V4L2_PIX_FMT_YVU420M ('YM21')</refentrytitle>
+ &manvol;
+ </refmeta>
+ <refnamediv>
+ <refname> <constant>V4L2_PIX_FMT_YVU420M</constant></refname>
+ <refpurpose>Variation of <constant>V4L2_PIX_FMT_YVU420</constant>
+ with planes non contiguous in memory. </refpurpose>
+ </refnamediv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>This is a multi-planar format, 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. The Cr data
+constitutes the second plane which 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>. The Cb data, just like the Cr plane, constitutes
+the third 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>
+
+ <para><constant>V4L2_PIX_FMT_YVU420M</constant> is intended to be
+used only in drivers and applications that support the multi-planar API,
+described in <xref linkend="planar-apis"/>. </para>
+
+ <example>
+ <title><constant>V4L2_PIX_FMT_YVU420M</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>start0&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>start0&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>start0&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>start0&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></entry></row>
+ <row>
+ <entry>start1&nbsp;+&nbsp;0:</entry>
+ <entry>Cr<subscript>00</subscript></entry>
+ <entry>Cr<subscript>01</subscript></entry>
+ </row>
+ <row>
+ <entry>start1&nbsp;+&nbsp;2:</entry>
+ <entry>Cr<subscript>10</subscript></entry>
+ <entry>Cr<subscript>11</subscript></entry>
+ </row>
+ <row><entry></entry></row>
+ <row>
+ <entry>start2&nbsp;+&nbsp;0:</entry>
+ <entry>Cb<subscript>00</subscript></entry>
+ <entry>Cb<subscript>01</subscript></entry>
+ </row>
+ <row>
+ <entry>start2&nbsp;+&nbsp;2:</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>