1 <refentry id=
"V4L2-PIX-FMT-NV12M">
3 <refentrytitle>V4L2_PIX_FMT_NV12M ('NV12M')
</refentrytitle>
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>
12 <title>Description
</title>
14 <para>This is a multi-planar, two-plane version of the YUV
4:
2:
0 format.
15 The 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
18 plane do not necessarily immediately follows the luma plane.
19 The luminance data occupies the first plane. The Y plane has one byte per pixel.
20 In the second plane there is a chrominance data with alternating chroma samples.
21 The CbCr plane is the same width, in bytes, as the Y plane (and of the image),
22 but is half as tall in pixels. Each CbCr pair belongs to four pixels. For example,
23 Cb
<subscript>0</subscript>/Cr
<subscript>0</subscript> belongs to
24 Y'
<subscript>00</subscript>, Y'
<subscript>01</subscript>,
25 Y'
<subscript>10</subscript>, Y'
<subscript>11</subscript>.
</para>
27 <para><constant>V4L2_PIX_FMT_NV12M
</constant> is intended to be
28 used only in drivers and applications that support the multi-planar API,
29 described in
<xref linkend=
"planar-apis"/>.
</para>
31 <para>If the Y plane has pad bytes after each row, then the
32 CbCr plane has as many pad bytes after its rows.
</para>
35 <title><constant>V4L2_PIX_FMT_NV12M
</constant> 4 × 4 pixel image
</title>
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*" />
45 <entry>start0
+
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>
52 <entry>start0
+
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>
59 <entry>start0
+
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>
66 <entry>start0
+
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>
76 <entry>start1
+
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>
83 <entry>start1
+
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>
96 <title>Color Sample Location.
</title>
98 <informaltable frame=
"none">
99 <tgroup cols=
"7" align=
"center">
103 <entry>0</entry><entry></entry><entry>1</entry><entry></entry>
104 <entry>2</entry><entry></entry><entry>3</entry>
108 <entry>Y
</entry><entry></entry><entry>Y
</entry><entry></entry>
109 <entry>Y
</entry><entry></entry><entry>Y
</entry>
113 <entry></entry><entry>C
</entry><entry></entry><entry></entry>
114 <entry></entry><entry>C
</entry><entry></entry>
118 <entry>Y
</entry><entry></entry><entry>Y
</entry><entry></entry>
119 <entry>Y
</entry><entry></entry><entry>Y
</entry>
126 <entry>Y
</entry><entry></entry><entry>Y
</entry><entry></entry>
127 <entry>Y
</entry><entry></entry><entry>Y
</entry>
131 <entry></entry><entry>C
</entry><entry></entry><entry></entry>
132 <entry></entry><entry>C
</entry><entry></entry>
136 <entry>Y
</entry><entry></entry><entry>Y
</entry><entry></entry>
137 <entry>Y
</entry><entry></entry><entry>Y
</entry>