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[media] V4L: add Y12I, Y8I and Z16 pixel format documentation
Add documentation for 3 formats, used by RealSense cameras like R200. Signed-off-by: Guennadi Liakhovetski <[email protected]> Acked-by: Sakari Ailus <[email protected]> Signed-off-by: Mauro Carvalho Chehab <[email protected]>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,49 @@ | ||
| <refentry id="V4L2-PIX-FMT-Y12I"> | ||
| <refmeta> | ||
| <refentrytitle>V4L2_PIX_FMT_Y12I ('Y12I')</refentrytitle> | ||
| &manvol; | ||
| </refmeta> | ||
| <refnamediv> | ||
| <refname><constant>V4L2_PIX_FMT_Y12I</constant></refname> | ||
| <refpurpose>Interleaved grey-scale image, e.g. from a stereo-pair</refpurpose> | ||
| </refnamediv> | ||
| <refsect1> | ||
| <title>Description</title> | ||
|
|
||
| <para>This is a grey-scale image with a depth of 12 bits per pixel, but with | ||
| pixels from 2 sources interleaved and bit-packed. Each pixel is stored in a | ||
| 24-bit word in the little-endian order. On a little-endian machine these pixels | ||
| can be deinterlaced using</para> | ||
|
|
||
| <para> | ||
| <programlisting> | ||
| __u8 *buf; | ||
| left0 = 0xfff & *(__u16 *)buf; | ||
| right0 = *(__u16 *)(buf + 1) >> 4; | ||
| </programlisting> | ||
| </para> | ||
|
|
||
| <example> | ||
| <title><constant>V4L2_PIX_FMT_Y12I</constant> 2 pixel data stream taking 3 bytes</title> | ||
|
|
||
| <formalpara> | ||
| <title>Bit-packed representation</title> | ||
| <para>pixels cross the byte boundary and have a ratio of 3 bytes for each | ||
| interleaved pixel. | ||
| <informaltable frame="all"> | ||
| <tgroup cols="3" align="center"> | ||
| <colspec align="left" colwidth="2*" /> | ||
| <tbody valign="top"> | ||
| <row> | ||
| <entry>Y'<subscript>0left[7:0]</subscript></entry> | ||
| <entry>Y'<subscript>0right[3:0]</subscript>Y'<subscript>0left[11:8]</subscript></entry> | ||
| <entry>Y'<subscript>0right[11:4]</subscript></entry> | ||
| </row> | ||
| </tbody> | ||
| </tgroup> | ||
| </informaltable> | ||
| </para> | ||
| </formalpara> | ||
| </example> | ||
| </refsect1> | ||
| </refentry> |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,80 @@ | ||
| <refentry id="V4L2-PIX-FMT-Y8I"> | ||
| <refmeta> | ||
| <refentrytitle>V4L2_PIX_FMT_Y8I ('Y8I ')</refentrytitle> | ||
| &manvol; | ||
| </refmeta> | ||
| <refnamediv> | ||
| <refname><constant>V4L2_PIX_FMT_Y8I</constant></refname> | ||
| <refpurpose>Interleaved grey-scale image, e.g. from a stereo-pair</refpurpose> | ||
| </refnamediv> | ||
| <refsect1> | ||
| <title>Description</title> | ||
|
|
||
| <para>This is a grey-scale image with a depth of 8 bits per pixel, but with | ||
| pixels from 2 sources interleaved. Each pixel is stored in a 16-bit word. E.g. | ||
| the R200 RealSense camera stores pixel from the left sensor in lower and from | ||
| the right sensor in the higher 8 bits.</para> | ||
|
|
||
| <example> | ||
| <title><constant>V4L2_PIX_FMT_Y8I</constant> 4 × 4 | ||
| pixel image</title> | ||
|
|
||
| <formalpara> | ||
| <title>Byte Order.</title> | ||
| <para>Each cell is one byte. | ||
| <informaltable frame="none"> | ||
| <tgroup cols="9" align="center"> | ||
| <colspec align="left" colwidth="2*" /> | ||
| <tbody valign="top"> | ||
| <row> | ||
| <entry>start + 0:</entry> | ||
| <entry>Y'<subscript>00left</subscript></entry> | ||
| <entry>Y'<subscript>00right</subscript></entry> | ||
| <entry>Y'<subscript>01left</subscript></entry> | ||
| <entry>Y'<subscript>01right</subscript></entry> | ||
| <entry>Y'<subscript>02left</subscript></entry> | ||
| <entry>Y'<subscript>02right</subscript></entry> | ||
| <entry>Y'<subscript>03left</subscript></entry> | ||
| <entry>Y'<subscript>03right</subscript></entry> | ||
| </row> | ||
| <row> | ||
| <entry>start + 8:</entry> | ||
| <entry>Y'<subscript>10left</subscript></entry> | ||
| <entry>Y'<subscript>10right</subscript></entry> | ||
| <entry>Y'<subscript>11left</subscript></entry> | ||
| <entry>Y'<subscript>11right</subscript></entry> | ||
| <entry>Y'<subscript>12left</subscript></entry> | ||
| <entry>Y'<subscript>12right</subscript></entry> | ||
| <entry>Y'<subscript>13left</subscript></entry> | ||
| <entry>Y'<subscript>13right</subscript></entry> | ||
| </row> | ||
| <row> | ||
| <entry>start + 16:</entry> | ||
| <entry>Y'<subscript>20left</subscript></entry> | ||
| <entry>Y'<subscript>20right</subscript></entry> | ||
| <entry>Y'<subscript>21left</subscript></entry> | ||
| <entry>Y'<subscript>21right</subscript></entry> | ||
| <entry>Y'<subscript>22left</subscript></entry> | ||
| <entry>Y'<subscript>22right</subscript></entry> | ||
| <entry>Y'<subscript>23left</subscript></entry> | ||
| <entry>Y'<subscript>23right</subscript></entry> | ||
| </row> | ||
| <row> | ||
| <entry>start + 24:</entry> | ||
| <entry>Y'<subscript>30left</subscript></entry> | ||
| <entry>Y'<subscript>30right</subscript></entry> | ||
| <entry>Y'<subscript>31left</subscript></entry> | ||
| <entry>Y'<subscript>31right</subscript></entry> | ||
| <entry>Y'<subscript>32left</subscript></entry> | ||
| <entry>Y'<subscript>32right</subscript></entry> | ||
| <entry>Y'<subscript>33left</subscript></entry> | ||
| <entry>Y'<subscript>33right</subscript></entry> | ||
| </row> | ||
| </tbody> | ||
| </tgroup> | ||
| </informaltable> | ||
| </para> | ||
| </formalpara> | ||
| </example> | ||
| </refsect1> | ||
| </refentry> |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,81 @@ | ||
| <refentry id="V4L2-PIX-FMT-Z16"> | ||
| <refmeta> | ||
| <refentrytitle>V4L2_PIX_FMT_Z16 ('Z16 ')</refentrytitle> | ||
| &manvol; | ||
| </refmeta> | ||
| <refnamediv> | ||
| <refname><constant>V4L2_PIX_FMT_Z16</constant></refname> | ||
| <refpurpose>Interleaved grey-scale image, e.g. from a stereo-pair</refpurpose> | ||
| </refnamediv> | ||
| <refsect1> | ||
| <title>Description</title> | ||
|
|
||
| <para>This is a 16-bit format, representing depth data. Each pixel is a | ||
| distance to the respective point in the image coordinates. Distance unit can | ||
| vary and has to be negotiated with the device separately. Each pixel is stored | ||
| in a 16-bit word in the little endian byte order. | ||
| </para> | ||
|
|
||
| <example> | ||
| <title><constant>V4L2_PIX_FMT_Z16</constant> 4 × 4 | ||
| pixel image</title> | ||
|
|
||
| <formalpara> | ||
| <title>Byte Order.</title> | ||
| <para>Each cell is one byte. | ||
| <informaltable frame="none"> | ||
| <tgroup cols="9" align="center"> | ||
| <colspec align="left" colwidth="2*" /> | ||
| <tbody valign="top"> | ||
| <row> | ||
| <entry>start + 0:</entry> | ||
| <entry>Z<subscript>00low</subscript></entry> | ||
| <entry>Z<subscript>00high</subscript></entry> | ||
| <entry>Z<subscript>01low</subscript></entry> | ||
| <entry>Z<subscript>01high</subscript></entry> | ||
| <entry>Z<subscript>02low</subscript></entry> | ||
| <entry>Z<subscript>02high</subscript></entry> | ||
| <entry>Z<subscript>03low</subscript></entry> | ||
| <entry>Z<subscript>03high</subscript></entry> | ||
| </row> | ||
| <row> | ||
| <entry>start + 8:</entry> | ||
| <entry>Z<subscript>10low</subscript></entry> | ||
| <entry>Z<subscript>10high</subscript></entry> | ||
| <entry>Z<subscript>11low</subscript></entry> | ||
| <entry>Z<subscript>11high</subscript></entry> | ||
| <entry>Z<subscript>12low</subscript></entry> | ||
| <entry>Z<subscript>12high</subscript></entry> | ||
| <entry>Z<subscript>13low</subscript></entry> | ||
| <entry>Z<subscript>13high</subscript></entry> | ||
| </row> | ||
| <row> | ||
| <entry>start + 16:</entry> | ||
| <entry>Z<subscript>20low</subscript></entry> | ||
| <entry>Z<subscript>20high</subscript></entry> | ||
| <entry>Z<subscript>21low</subscript></entry> | ||
| <entry>Z<subscript>21high</subscript></entry> | ||
| <entry>Z<subscript>22low</subscript></entry> | ||
| <entry>Z<subscript>22high</subscript></entry> | ||
| <entry>Z<subscript>23low</subscript></entry> | ||
| <entry>Z<subscript>23high</subscript></entry> | ||
| </row> | ||
| <row> | ||
| <entry>start + 24:</entry> | ||
| <entry>Z<subscript>30low</subscript></entry> | ||
| <entry>Z<subscript>30high</subscript></entry> | ||
| <entry>Z<subscript>31low</subscript></entry> | ||
| <entry>Z<subscript>31high</subscript></entry> | ||
| <entry>Z<subscript>32low</subscript></entry> | ||
| <entry>Z<subscript>32high</subscript></entry> | ||
| <entry>Z<subscript>33low</subscript></entry> | ||
| <entry>Z<subscript>33high</subscript></entry> | ||
| </row> | ||
| </tbody> | ||
| </tgroup> | ||
| </informaltable> | ||
| </para> | ||
| </formalpara> | ||
| </example> | ||
| </refsect1> | ||
| </refentry> |
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