Laurent Pinchart | 8493054 | 2013-06-26 09:46:42 -0300 | [diff] [blame] | 1 | <refentry> |
| 2 | <refmeta> |
| 3 | <refentrytitle>V4L2_PIX_FMT_NV16M ('NM16'), V4L2_PIX_FMT_NV61M ('NM61')</refentrytitle> |
| 4 | &manvol; |
| 5 | </refmeta> |
| 6 | <refnamediv> |
| 7 | <refname id="V4L2-PIX-FMT-NV16M"><constant>V4L2_PIX_FMT_NV16M</constant></refname> |
| 8 | <refname id="V4L2-PIX-FMT-NV61M"><constant>V4L2_PIX_FMT_NV61M</constant></refname> |
| 9 | <refpurpose>Variation of <constant>V4L2_PIX_FMT_NV16</constant> and <constant>V4L2_PIX_FMT_NV61</constant> with planes |
| 10 | non contiguous in memory. </refpurpose> |
| 11 | </refnamediv> |
| 12 | <refsect1> |
| 13 | <title>Description</title> |
| 14 | |
| 15 | <para>This is a multi-planar, two-plane version of the YUV 4:2:0 format. |
| 16 | The three components are separated into two sub-images or planes. |
| 17 | <constant>V4L2_PIX_FMT_NV16M</constant> differs from <constant>V4L2_PIX_FMT_NV16 |
| 18 | </constant> in that the two planes are non-contiguous in memory, i.e. the chroma |
| 19 | plane does not necessarily immediately follows the luma plane. |
| 20 | The luminance data occupies the first plane. The Y plane has one byte per pixel. |
| 21 | In the second plane there is chrominance data with alternating chroma samples. |
| 22 | The CbCr plane is the same width and height, in bytes, as the Y plane. |
| 23 | Each CbCr pair belongs to four pixels. For example, |
| 24 | Cb<subscript>0</subscript>/Cr<subscript>0</subscript> belongs to |
| 25 | Y'<subscript>00</subscript>, Y'<subscript>01</subscript>, |
| 26 | Y'<subscript>10</subscript>, Y'<subscript>11</subscript>. |
| 27 | <constant>V4L2_PIX_FMT_NV61M</constant> is the same as <constant>V4L2_PIX_FMT_NV16M</constant> |
| 28 | except the Cb and Cr bytes are swapped, the CrCb plane starts with a Cr byte.</para> |
| 29 | |
| 30 | <para><constant>V4L2_PIX_FMT_NV16M</constant> and |
| 31 | <constant>V4L2_PIX_FMT_NV61M</constant> are intended to be used only in drivers |
| 32 | and applications that support the multi-planar API, described in |
| 33 | <xref linkend="planar-apis"/>. </para> |
| 34 | |
| 35 | <example> |
| 36 | <title><constant>V4L2_PIX_FMT_NV16M</constant> 4 × 4 pixel image</title> |
| 37 | |
| 38 | <formalpara> |
| 39 | <title>Byte Order.</title> |
| 40 | <para>Each cell is one byte. |
| 41 | <informaltable frame="none"> |
| 42 | <tgroup cols="5" align="center"> |
| 43 | <colspec align="left" colwidth="2*" /> |
| 44 | <tbody valign="top"> |
| 45 | <row> |
| 46 | <entry>start0 + 0:</entry> |
| 47 | <entry>Y'<subscript>00</subscript></entry> |
| 48 | <entry>Y'<subscript>01</subscript></entry> |
| 49 | <entry>Y'<subscript>02</subscript></entry> |
| 50 | <entry>Y'<subscript>03</subscript></entry> |
| 51 | </row> |
| 52 | <row> |
| 53 | <entry>start0 + 4:</entry> |
| 54 | <entry>Y'<subscript>10</subscript></entry> |
| 55 | <entry>Y'<subscript>11</subscript></entry> |
| 56 | <entry>Y'<subscript>12</subscript></entry> |
| 57 | <entry>Y'<subscript>13</subscript></entry> |
| 58 | </row> |
| 59 | <row> |
| 60 | <entry>start0 + 8:</entry> |
| 61 | <entry>Y'<subscript>20</subscript></entry> |
| 62 | <entry>Y'<subscript>21</subscript></entry> |
| 63 | <entry>Y'<subscript>22</subscript></entry> |
| 64 | <entry>Y'<subscript>23</subscript></entry> |
| 65 | </row> |
| 66 | <row> |
| 67 | <entry>start0 + 12:</entry> |
| 68 | <entry>Y'<subscript>30</subscript></entry> |
| 69 | <entry>Y'<subscript>31</subscript></entry> |
| 70 | <entry>Y'<subscript>32</subscript></entry> |
| 71 | <entry>Y'<subscript>33</subscript></entry> |
| 72 | </row> |
| 73 | <row> |
| 74 | <entry></entry> |
| 75 | </row> |
| 76 | <row> |
| 77 | <entry>start1 + 0:</entry> |
| 78 | <entry>Cb<subscript>00</subscript></entry> |
| 79 | <entry>Cr<subscript>00</subscript></entry> |
| 80 | <entry>Cb<subscript>02</subscript></entry> |
| 81 | <entry>Cr<subscript>02</subscript></entry> |
| 82 | </row> |
| 83 | <row> |
| 84 | <entry>start1 + 4:</entry> |
| 85 | <entry>Cb<subscript>10</subscript></entry> |
| 86 | <entry>Cr<subscript>10</subscript></entry> |
| 87 | <entry>Cb<subscript>12</subscript></entry> |
| 88 | <entry>Cr<subscript>12</subscript></entry> |
| 89 | </row> |
| 90 | <row> |
| 91 | <entry>start1 + 8:</entry> |
| 92 | <entry>Cb<subscript>20</subscript></entry> |
| 93 | <entry>Cr<subscript>20</subscript></entry> |
| 94 | <entry>Cb<subscript>22</subscript></entry> |
| 95 | <entry>Cr<subscript>22</subscript></entry> |
| 96 | </row> |
| 97 | <row> |
| 98 | <entry>start1 + 12:</entry> |
| 99 | <entry>Cb<subscript>30</subscript></entry> |
| 100 | <entry>Cr<subscript>30</subscript></entry> |
| 101 | <entry>Cb<subscript>32</subscript></entry> |
| 102 | <entry>Cr<subscript>32</subscript></entry> |
| 103 | </row> |
| 104 | </tbody> |
| 105 | </tgroup> |
| 106 | </informaltable> |
| 107 | </para> |
| 108 | </formalpara> |
| 109 | |
| 110 | <formalpara> |
| 111 | <title>Color Sample Location.</title> |
| 112 | <para> |
| 113 | <informaltable frame="none"> |
| 114 | <tgroup cols="7" align="center"> |
| 115 | <tbody valign="top"> |
| 116 | <row> |
| 117 | <entry></entry> |
| 118 | <entry>0</entry><entry></entry><entry>1</entry><entry></entry> |
| 119 | <entry>2</entry><entry></entry><entry>3</entry> |
| 120 | </row> |
| 121 | <row> |
| 122 | <entry>0</entry> |
| 123 | <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry> |
| 124 | <entry>Y</entry><entry></entry><entry>Y</entry> |
| 125 | </row> |
| 126 | <row> |
| 127 | <entry></entry> |
| 128 | <entry></entry><entry>C</entry><entry></entry><entry></entry> |
| 129 | <entry></entry><entry>C</entry><entry></entry> |
| 130 | </row> |
| 131 | <row> |
| 132 | <entry>1</entry> |
| 133 | <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry> |
| 134 | <entry>Y</entry><entry></entry><entry>Y</entry> |
| 135 | </row> |
| 136 | <row> |
| 137 | <entry></entry> |
| 138 | <entry></entry><entry>C</entry><entry></entry><entry></entry> |
| 139 | <entry></entry><entry>C</entry><entry></entry> |
| 140 | </row> |
| 141 | <row> |
| 142 | <entry></entry> |
| 143 | </row> |
| 144 | <row> |
| 145 | <entry>2</entry> |
| 146 | <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry> |
| 147 | <entry>Y</entry><entry></entry><entry>Y</entry> |
| 148 | </row> |
| 149 | <row> |
| 150 | <entry></entry> |
| 151 | <entry></entry><entry>C</entry><entry></entry><entry></entry> |
| 152 | <entry></entry><entry>C</entry><entry></entry> |
| 153 | </row> |
| 154 | <row> |
| 155 | <entry>3</entry> |
| 156 | <entry>Y</entry><entry></entry><entry>Y</entry><entry></entry> |
| 157 | <entry>Y</entry><entry></entry><entry>Y</entry> |
| 158 | </row> |
| 159 | <row> |
| 160 | <entry></entry> |
| 161 | <entry></entry><entry>C</entry><entry></entry><entry></entry> |
| 162 | <entry></entry><entry>C</entry><entry></entry> |
| 163 | </row> |
| 164 | </tbody> |
| 165 | </tgroup> |
| 166 | </informaltable> |
| 167 | </para> |
| 168 | </formalpara> |
| 169 | </example> |
| 170 | </refsect1> |
| 171 | </refentry> |