aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/DocBook/media/v4l/pixfmt-nv12m.xml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DocBook/media/v4l/pixfmt-nv12m.xml')
-rw-r--r--Documentation/DocBook/media/v4l/pixfmt-nv12m.xml154
1 files changed, 154 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/pixfmt-nv12m.xml b/Documentation/DocBook/media/v4l/pixfmt-nv12m.xml
new file mode 100644
index 000000000000..c9e166d9ded8
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/pixfmt-nv12m.xml
@@ -0,0 +1,154 @@
1 <refentry id="V4L2-PIX-FMT-NV12M">
2 <refmeta>
3 <refentrytitle>V4L2_PIX_FMT_NV12M ('NV12M')</refentrytitle>
4 &manvol;
5 </refmeta>
6 <refnamediv>
7 <refname> <constant>V4L2_PIX_FMT_NV12M</constant></refname>
8 <refpurpose>Variation of <constant>V4L2_PIX_FMT_NV12</constant> with planes
9 non contiguous in memory. </refpurpose>
10 </refnamediv>
11 <refsect1>
12 <title>Description</title>
13
14 <para>This is a multi-planar, two-plane version of the YUV 4:2:0 format.
15The three components are separated into two sub-images or planes.
16<constant>V4L2_PIX_FMT_NV12M</constant> differs from <constant>V4L2_PIX_FMT_NV12
17</constant> in that the two planes are non-contiguous in memory, i.e. the chroma
18plane do not necessarily immediately follows the luma plane.
19The luminance data occupies the first plane. The Y plane has one byte per pixel.
20In the second plane there is a chrominance data with alternating chroma samples.
21The CbCr plane is the same width, in bytes, as the Y plane (and of the image),
22but is half as tall in pixels. Each CbCr pair belongs to four pixels. For example,
23Cb<subscript>0</subscript>/Cr<subscript>0</subscript> belongs to
24Y'<subscript>00</subscript>, Y'<subscript>01</subscript>,
25Y'<subscript>10</subscript>, Y'<subscript>11</subscript>. </para>
26
27 <para><constant>V4L2_PIX_FMT_NV12M</constant> is intended to be
28used only in drivers and applications that support the multi-planar API,
29described in <xref linkend="planar-apis"/>. </para>
30
31 <para>If the Y plane has pad bytes after each row, then the
32CbCr plane has as many pad bytes after its rows.</para>
33
34 <example>
35 <title><constant>V4L2_PIX_FMT_NV12M</constant> 4 &times; 4 pixel image</title>
36
37 <formalpara>
38 <title>Byte Order.</title>
39 <para>Each cell is one byte.
40 <informaltable frame="none">
41 <tgroup cols="5" align="center">
42 <colspec align="left" colwidth="2*" />
43 <tbody valign="top">
44 <row>
45 <entry>start0&nbsp;+&nbsp;0:</entry>
46 <entry>Y'<subscript>00</subscript></entry>
47 <entry>Y'<subscript>01</subscript></entry>
48 <entry>Y'<subscript>02</subscript></entry>
49 <entry>Y'<subscript>03</subscript></entry>
50 </row>
51 <row>
52 <entry>start0&nbsp;+&nbsp;4:</entry>
53 <entry>Y'<subscript>10</subscript></entry>
54 <entry>Y'<subscript>11</subscript></entry>
55 <entry>Y'<subscript>12</subscript></entry>
56 <entry>Y'<subscript>13</subscript></entry>
57 </row>
58 <row>
59 <entry>start0&nbsp;+&nbsp;8:</entry>
60 <entry>Y'<subscript>20</subscript></entry>
61 <entry>Y'<subscript>21</subscript></entry>
62 <entry>Y'<subscript>22</subscript></entry>
63 <entry>Y'<subscript>23</subscript></entry>
64 </row>
65 <row>
66 <entry>start0&nbsp;+&nbsp;12:</entry>
67 <entry>Y'<subscript>30</subscript></entry>
68 <entry>Y'<subscript>31</subscript></entry>
69 <entry>Y'<subscript>32</subscript></entry>
70 <entry>Y'<subscript>33</subscript></entry>
71 </row>
72 <row>
73 <entry></entry>
74 </row>
75 <row>
76 <entry>start1&nbsp;+&nbsp;0:</entry>
77 <entry>Cb<subscript>00</subscript></entry>
78 <entry>Cr<subscript>00</subscript></entry>
79 <entry>Cb<subscript>01</subscript></entry>
80 <entry>Cr<subscript>01</subscript></entry>
81 </row>
82 <row>
83 <entry>start1&nbsp;+&nbsp;4:</entry>
84 <entry>Cb<subscript>10</subscript></entry>
85 <entry>Cr<subscript>10</subscript></entry>
86 <entry>Cb<subscript>11</subscript></entry>
87 <entry>Cr<subscript>11</subscript></entry>
88 </row>
89 </tbody>
90 </tgroup>
91 </informaltable>
92 </para>
93 </formalpara>
94
95 <formalpara>
96 <title>Color Sample Location.</title>
97 <para>
98 <informaltable frame="none">
99 <tgroup cols="7" align="center">
100 <tbody valign="top">
101 <row>
102 <entry></entry>
103 <entry>0</entry><entry></entry><entry>1</entry><entry></entry>
104 <entry>2</entry><entry></entry><entry>3</entry>
105 </row>
106 <row>
107 <entry>0</entry>
108 <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
109 <entry>Y</entry><entry></entry><entry>Y</entry>
110 </row>
111 <row>
112 <entry></entry>
113 <entry></entry><entry>C</entry><entry></entry><entry></entry>
114 <entry></entry><entry>C</entry><entry></entry>
115 </row>
116 <row>
117 <entry>1</entry>
118 <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
119 <entry>Y</entry><entry></entry><entry>Y</entry>
120 </row>
121 <row>
122 <entry></entry>
123 </row>
124 <row>
125 <entry>2</entry>
126 <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
127 <entry>Y</entry><entry></entry><entry>Y</entry>
128 </row>
129 <row>
130 <entry></entry>
131 <entry></entry><entry>C</entry><entry></entry><entry></entry>
132 <entry></entry><entry>C</entry><entry></entry>
133 </row>
134 <row>
135 <entry>3</entry>
136 <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry>
137 <entry>Y</entry><entry></entry><entry>Y</entry>
138 </row>
139 </tbody>
140 </tgroup>
141 </informaltable>
142 </para>
143 </formalpara>
144 </example>
145 </refsect1>
146 </refentry>
147
148 <!--
149Local Variables:
150mode: sgml
151sgml-parent-document: "pixfmt.sgml"
152indent-tabs-mode: nil
153End:
154 -->
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-11 06:09:08 -0500