| Laurent Pinchart | 0b9eabd | 2011-12-13 14:02:27 +0100 | [diff] [blame] | 1 | <refentry> |
| 2 | <refmeta> |
| 3 | <refentrytitle>V4L2_PIX_FMT_NV24 ('NV24'), V4L2_PIX_FMT_NV42 ('NV42')</refentrytitle> |
| 4 | &manvol; |
| 5 | </refmeta> |
| 6 | <refnamediv> |
| 7 | <refname id="V4L2-PIX-FMT-NV24"><constant>V4L2_PIX_FMT_NV24</constant></refname> |
| 8 | <refname id="V4L2-PIX-FMT-NV42"><constant>V4L2_PIX_FMT_NV42</constant></refname> |
| 9 | <refpurpose>Formats with full horizontal and vertical |
| 10 | chroma resolutions, also known as YUV 4:4:4. 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 4:4:4 format. The three |
| 18 | components are separated into two sub-images or planes. The Y plane is |
| 19 | first, with each Y sample stored in one byte per pixel. For |
| 20 | <constant>V4L2_PIX_FMT_NV24</constant>, a combined CbCr plane |
| 21 | immediately follows the Y plane in memory. The CbCr plane has the same |
| 22 | width and height, in pixels, as the Y plane (and the image). Each line |
| 23 | contains one CbCr pair per pixel, with each Cb and Cr sample stored in |
| 24 | one byte. <constant>V4L2_PIX_FMT_NV42</constant> is the same except that |
| 25 | the Cb and Cr samples are swapped, the CrCb plane starts with a Cr |
| 26 | sample.</para> |
| 27 | |
| 28 | <para>If the Y plane has pad bytes after each row, then the CbCr plane |
| 29 | has twice as many pad bytes after its rows.</para> |
| 30 | |
| 31 | <example> |
| 32 | <title><constant>V4L2_PIX_FMT_NV24</constant> 4 × 4 |
| 33 | pixel image</title> |
| 34 | |
| 35 | <formalpara> |
| 36 | <title>Byte Order.</title> |
| 37 | <para>Each cell is one byte. |
| 38 | <informaltable frame="none"> |
| 39 | <tgroup cols="9" align="center"> |
| 40 | <colspec align="left" colwidth="2*" /> |
| 41 | <tbody valign="top"> |
| 42 | <row> |
| 43 | <entry>start + 0:</entry> |
| 44 | <entry>Y'<subscript>00</subscript></entry> |
| 45 | <entry>Y'<subscript>01</subscript></entry> |
| 46 | <entry>Y'<subscript>02</subscript></entry> |
| 47 | <entry>Y'<subscript>03</subscript></entry> |
| 48 | </row> |
| 49 | <row> |
| 50 | <entry>start + 4:</entry> |
| 51 | <entry>Y'<subscript>10</subscript></entry> |
| 52 | <entry>Y'<subscript>11</subscript></entry> |
| 53 | <entry>Y'<subscript>12</subscript></entry> |
| 54 | <entry>Y'<subscript>13</subscript></entry> |
| 55 | </row> |
| 56 | <row> |
| 57 | <entry>start + 8:</entry> |
| 58 | <entry>Y'<subscript>20</subscript></entry> |
| 59 | <entry>Y'<subscript>21</subscript></entry> |
| 60 | <entry>Y'<subscript>22</subscript></entry> |
| 61 | <entry>Y'<subscript>23</subscript></entry> |
| 62 | </row> |
| 63 | <row> |
| 64 | <entry>start + 12:</entry> |
| 65 | <entry>Y'<subscript>30</subscript></entry> |
| 66 | <entry>Y'<subscript>31</subscript></entry> |
| 67 | <entry>Y'<subscript>32</subscript></entry> |
| 68 | <entry>Y'<subscript>33</subscript></entry> |
| 69 | </row> |
| 70 | <row> |
| 71 | <entry>start + 16:</entry> |
| 72 | <entry>Cb<subscript>00</subscript></entry> |
| 73 | <entry>Cr<subscript>00</subscript></entry> |
| 74 | <entry>Cb<subscript>01</subscript></entry> |
| 75 | <entry>Cr<subscript>01</subscript></entry> |
| 76 | <entry>Cb<subscript>02</subscript></entry> |
| 77 | <entry>Cr<subscript>02</subscript></entry> |
| 78 | <entry>Cb<subscript>03</subscript></entry> |
| 79 | <entry>Cr<subscript>03</subscript></entry> |
| 80 | </row> |
| 81 | <row> |
| 82 | <entry>start + 24:</entry> |
| 83 | <entry>Cb<subscript>10</subscript></entry> |
| 84 | <entry>Cr<subscript>10</subscript></entry> |
| 85 | <entry>Cb<subscript>11</subscript></entry> |
| 86 | <entry>Cr<subscript>11</subscript></entry> |
| 87 | <entry>Cb<subscript>12</subscript></entry> |
| 88 | <entry>Cr<subscript>12</subscript></entry> |
| 89 | <entry>Cb<subscript>13</subscript></entry> |
| 90 | <entry>Cr<subscript>13</subscript></entry> |
| 91 | </row> |
| 92 | <row> |
| 93 | <entry>start + 32:</entry> |
| 94 | <entry>Cb<subscript>20</subscript></entry> |
| 95 | <entry>Cr<subscript>20</subscript></entry> |
| 96 | <entry>Cb<subscript>21</subscript></entry> |
| 97 | <entry>Cr<subscript>21</subscript></entry> |
| 98 | <entry>Cb<subscript>22</subscript></entry> |
| 99 | <entry>Cr<subscript>22</subscript></entry> |
| 100 | <entry>Cb<subscript>23</subscript></entry> |
| 101 | <entry>Cr<subscript>23</subscript></entry> |
| 102 | </row> |
| 103 | <row> |
| 104 | <entry>start + 40:</entry> |
| 105 | <entry>Cb<subscript>30</subscript></entry> |
| 106 | <entry>Cr<subscript>30</subscript></entry> |
| 107 | <entry>Cb<subscript>31</subscript></entry> |
| 108 | <entry>Cr<subscript>31</subscript></entry> |
| 109 | <entry>Cb<subscript>32</subscript></entry> |
| 110 | <entry>Cr<subscript>32</subscript></entry> |
| 111 | <entry>Cb<subscript>33</subscript></entry> |
| 112 | <entry>Cr<subscript>33</subscript></entry> |
| 113 | </row> |
| 114 | </tbody> |
| 115 | </tgroup> |
| 116 | </informaltable> |
| 117 | </para> |
| 118 | </formalpara> |
| 119 | </example> |
| 120 | </refsect1> |
| 121 | </refentry> |