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8e080c2e MCC |
1 | <refentry> |
2 | <refmeta> | |
3 | <refentrytitle>V4L2_PIX_FMT_NV16 ('NV16'), V4L2_PIX_FMT_NV61 ('NV61')</refentrytitle> | |
4 | &manvol; | |
5 | </refmeta> | |
6 | <refnamediv> | |
7 | <refname id="V4L2-PIX-FMT-NV16"><constant>V4L2_PIX_FMT_NV16</constant></refname> | |
8 | <refname id="V4L2-PIX-FMT-NV61"><constant>V4L2_PIX_FMT_NV61</constant></refname> | |
9 | <refpurpose>Formats with ½ horizontal | |
10 | chroma resolution, also known as YUV 4:2:2. One luminance and one | |
11 | chrominance plane with alternating chroma samples as opposed to | |
12 | <constant>V4L2_PIX_FMT_YVU420</constant></refpurpose> | |
13 | </refnamediv> | |
14 | <refsect1> | |
15 | <title>Description</title> | |
16 | ||
17 | <para>These are two-plane versions of the YUV 4:2:2 format. | |
18 | The three components are separated into two sub-images or planes. The | |
19 | Y plane is first. The Y plane has one byte per pixel. For | |
20 | <constant>V4L2_PIX_FMT_NV16</constant>, a combined CbCr plane | |
21 | immediately follows the Y plane in memory. The CbCr plane is the same | |
22 | width and height, in bytes, as the Y plane (and of the image). | |
23 | Each CbCr pair belongs to two pixels. For example, | |
24 | Cb<subscript>0</subscript>/Cr<subscript>0</subscript> belongs to | |
25 | Y'<subscript>00</subscript>, Y'<subscript>01</subscript>. | |
26 | <constant>V4L2_PIX_FMT_NV61</constant> is the same except the Cb and | |
27 | Cr bytes are swapped, the CrCb plane starts with a Cr byte.</para> | |
28 | ||
29 | <para>If the Y plane has pad bytes after each row, then the | |
30 | CbCr plane has as many pad bytes after its rows.</para> | |
31 | ||
32 | <example> | |
33 | <title><constant>V4L2_PIX_FMT_NV16</constant> 4 × 4 | |
34 | pixel image</title> | |
35 | ||
36 | <formalpara> | |
37 | <title>Byte Order.</title> | |
38 | <para>Each cell is one byte. | |
39 | <informaltable frame="none"> | |
40 | <tgroup cols="5" align="center"> | |
41 | <colspec align="left" colwidth="2*" /> | |
42 | <tbody valign="top"> | |
43 | <row> | |
44 | <entry>start + 0:</entry> | |
45 | <entry>Y'<subscript>00</subscript></entry> | |
46 | <entry>Y'<subscript>01</subscript></entry> | |
47 | <entry>Y'<subscript>02</subscript></entry> | |
48 | <entry>Y'<subscript>03</subscript></entry> | |
49 | </row> | |
50 | <row> | |
51 | <entry>start + 4:</entry> | |
52 | <entry>Y'<subscript>10</subscript></entry> | |
53 | <entry>Y'<subscript>11</subscript></entry> | |
54 | <entry>Y'<subscript>12</subscript></entry> | |
55 | <entry>Y'<subscript>13</subscript></entry> | |
56 | </row> | |
57 | <row> | |
58 | <entry>start + 8:</entry> | |
59 | <entry>Y'<subscript>20</subscript></entry> | |
60 | <entry>Y'<subscript>21</subscript></entry> | |
61 | <entry>Y'<subscript>22</subscript></entry> | |
62 | <entry>Y'<subscript>23</subscript></entry> | |
63 | </row> | |
64 | <row> | |
65 | <entry>start + 12:</entry> | |
66 | <entry>Y'<subscript>30</subscript></entry> | |
67 | <entry>Y'<subscript>31</subscript></entry> | |
68 | <entry>Y'<subscript>32</subscript></entry> | |
69 | <entry>Y'<subscript>33</subscript></entry> | |
70 | </row> | |
71 | <row> | |
72 | <entry>start + 16:</entry> | |
73 | <entry>Cb<subscript>00</subscript></entry> | |
74 | <entry>Cr<subscript>00</subscript></entry> | |
75 | <entry>Cb<subscript>01</subscript></entry> | |
76 | <entry>Cr<subscript>01</subscript></entry> | |
77 | </row> | |
78 | <row> | |
79 | <entry>start + 20:</entry> | |
80 | <entry>Cb<subscript>10</subscript></entry> | |
81 | <entry>Cr<subscript>10</subscript></entry> | |
82 | <entry>Cb<subscript>11</subscript></entry> | |
83 | <entry>Cr<subscript>11</subscript></entry> | |
84 | </row> | |
85 | <row> | |
86 | <entry>start + 24:</entry> | |
87 | <entry>Cb<subscript>20</subscript></entry> | |
88 | <entry>Cr<subscript>20</subscript></entry> | |
89 | <entry>Cb<subscript>21</subscript></entry> | |
90 | <entry>Cr<subscript>21</subscript></entry> | |
91 | </row> | |
92 | <row> | |
93 | <entry>start + 28:</entry> | |
94 | <entry>Cb<subscript>30</subscript></entry> | |
95 | <entry>Cr<subscript>30</subscript></entry> | |
96 | <entry>Cb<subscript>31</subscript></entry> | |
97 | <entry>Cr<subscript>31</subscript></entry> | |
98 | </row> | |
99 | </tbody> | |
100 | </tgroup> | |
101 | </informaltable> | |
102 | </para> | |
103 | </formalpara> | |
104 | ||
105 | <formalpara> | |
106 | <title>Color Sample Location.</title> | |
107 | <para> | |
108 | <informaltable frame="none"> | |
109 | <tgroup cols="7" align="center"> | |
110 | <tbody valign="top"> | |
111 | <row> | |
112 | <entry></entry> | |
113 | <entry>0</entry><entry></entry><entry>1</entry><entry></entry> | |
114 | <entry>2</entry><entry></entry><entry>3</entry> | |
115 | </row> | |
116 | <row> | |
117 | <entry>0</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 | <entry></entry><entry>C</entry><entry></entry><entry></entry> | |
124 | <entry></entry><entry>C</entry><entry></entry> | |
125 | </row> | |
126 | <row> | |
127 | <entry>1</entry> | |
128 | <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry> | |
129 | <entry>Y</entry><entry></entry><entry>Y</entry> | |
130 | </row> | |
131 | <row> | |
132 | <entry></entry> | |
133 | <entry></entry><entry>C</entry><entry></entry><entry></entry> | |
134 | <entry></entry><entry>C</entry><entry></entry> | |
135 | </row> | |
136 | <row> | |
137 | <entry></entry> | |
138 | </row> | |
139 | <row> | |
140 | <entry>2</entry> | |
141 | <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry> | |
142 | <entry>Y</entry><entry></entry><entry>Y</entry> | |
143 | </row> | |
144 | <row> | |
145 | <entry></entry> | |
146 | <entry></entry><entry>C</entry><entry></entry><entry></entry> | |
147 | <entry></entry><entry>C</entry><entry></entry> | |
148 | </row> | |
149 | <row> | |
150 | <entry>3</entry> | |
151 | <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry> | |
152 | <entry>Y</entry><entry></entry><entry>Y</entry> | |
153 | </row> | |
154 | <row> | |
155 | <entry></entry> | |
156 | <entry></entry><entry>C</entry><entry></entry><entry></entry> | |
157 | <entry></entry><entry>C</entry><entry></entry> | |
158 | </row> | |
159 | </tbody> | |
160 | </tgroup> | |
161 | </informaltable> | |
162 | </para> | |
163 | </formalpara> | |
164 | </example> | |
165 | </refsect1> | |
166 | </refentry> |