* [PATCH v2] V4L: add Y12I, Y8I and Z16 pixel format documentation
@ 2016-01-18 14:32 Guennadi Liakhovetski
2016-01-19 13:19 ` Sakari Ailus
0 siblings, 1 reply; 4+ messages in thread
From: Guennadi Liakhovetski @ 2016-01-18 14:32 UTC (permalink / raw)
To: Linux Media Mailing List; +Cc: Sakari Ailus, Aviv Greenberg, Hans Verkuil
Add documentation for 3 formats, used by RealSense cameras like R200.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
---
Documentation/DocBook/media/v4l/pixfmt-y12i.xml | 49 +++++++++++++++
Documentation/DocBook/media/v4l/pixfmt-y8i.xml | 80 ++++++++++++++++++++++++
Documentation/DocBook/media/v4l/pixfmt-z16.xml | 81 +++++++++++++++++++++++++
Documentation/DocBook/media/v4l/pixfmt.xml | 10 +++
4 files changed, 220 insertions(+)
create mode 100644 Documentation/DocBook/media/v4l/pixfmt-y12i.xml
create mode 100644 Documentation/DocBook/media/v4l/pixfmt-y8i.xml
create mode 100644 Documentation/DocBook/media/v4l/pixfmt-z16.xml
diff --git a/Documentation/DocBook/media/v4l/pixfmt-y12i.xml b/Documentation/DocBook/media/v4l/pixfmt-y12i.xml
new file mode 100644
index 0000000..4a2d1e5
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/pixfmt-y12i.xml
@@ -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>
diff --git a/Documentation/DocBook/media/v4l/pixfmt-y8i.xml b/Documentation/DocBook/media/v4l/pixfmt-y8i.xml
new file mode 100644
index 0000000..99f389d
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/pixfmt-y8i.xml
@@ -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>
diff --git a/Documentation/DocBook/media/v4l/pixfmt-z16.xml b/Documentation/DocBook/media/v4l/pixfmt-z16.xml
new file mode 100644
index 0000000..3d87e4b
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/pixfmt-z16.xml
@@ -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>
diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml
index d871245..9924732 100644
--- a/Documentation/DocBook/media/v4l/pixfmt.xml
+++ b/Documentation/DocBook/media/v4l/pixfmt.xml
@@ -1620,6 +1620,8 @@ information.</para>
&sub-y10b;
&sub-y16;
&sub-y16-be;
+ &sub-y8i;
+ &sub-y12i;
&sub-uv8;
&sub-yuyv;
&sub-uyvy;
@@ -1641,6 +1643,14 @@ information.</para>
&sub-m420;
</section>
+ <section id="depth-formats">
+ <title>Depth Formats</title>
+ <para>Depth data provides distance to points, mapped onto the image plane
+ </para>
+
+ &sub-z16;
+ </section>
+
<section>
<title>Compressed Formats</title>
--
1.9.3
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] V4L: add Y12I, Y8I and Z16 pixel format documentation
2016-01-18 14:32 [PATCH v2] V4L: add Y12I, Y8I and Z16 pixel format documentation Guennadi Liakhovetski
@ 2016-01-19 13:19 ` Sakari Ailus
2016-01-25 16:15 ` Guennadi Liakhovetski
0 siblings, 1 reply; 4+ messages in thread
From: Sakari Ailus @ 2016-01-19 13:19 UTC (permalink / raw)
To: Guennadi Liakhovetski, Linux Media Mailing List
Cc: Aviv Greenberg, Hans Verkuil, Laurent Pinchart
Hi Guennadi,
Guennadi Liakhovetski wrote:
> Add documentation for 3 formats, used by RealSense cameras like R200.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
> Documentation/DocBook/media/v4l/pixfmt-y12i.xml | 49 +++++++++++++++
> Documentation/DocBook/media/v4l/pixfmt-y8i.xml | 80 ++++++++++++++++++++++++
> Documentation/DocBook/media/v4l/pixfmt-z16.xml | 81 +++++++++++++++++++++++++
> Documentation/DocBook/media/v4l/pixfmt.xml | 10 +++
> 4 files changed, 220 insertions(+)
> create mode 100644 Documentation/DocBook/media/v4l/pixfmt-y12i.xml
> create mode 100644 Documentation/DocBook/media/v4l/pixfmt-y8i.xml
> create mode 100644 Documentation/DocBook/media/v4l/pixfmt-z16.xml
>
> diff --git a/Documentation/DocBook/media/v4l/pixfmt-y12i.xml b/Documentation/DocBook/media/v4l/pixfmt-y12i.xml
> new file mode 100644
> index 0000000..4a2d1e5
> --- /dev/null
> +++ b/Documentation/DocBook/media/v4l/pixfmt-y12i.xml
> @@ -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>
> diff --git a/Documentation/DocBook/media/v4l/pixfmt-y8i.xml b/Documentation/DocBook/media/v4l/pixfmt-y8i.xml
> new file mode 100644
> index 0000000..99f389d
> --- /dev/null
> +++ b/Documentation/DocBook/media/v4l/pixfmt-y8i.xml
> @@ -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>
> diff --git a/Documentation/DocBook/media/v4l/pixfmt-z16.xml b/Documentation/DocBook/media/v4l/pixfmt-z16.xml
> new file mode 100644
> index 0000000..3d87e4b
> --- /dev/null
> +++ b/Documentation/DocBook/media/v4l/pixfmt-z16.xml
> @@ -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.
I think we really need a way to convey the unit (and prefix) information
to the user. Considering the same should be done to controls, it'd be
logical to do that at the same time with the controls.
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
I'd like to have Hans's and/or Laurent's ack on this as well.
Unless the original patch requires changes, it could be re-applied if no
changes are requested to it. My understanding is that the issue mainly
was the missing documentation, i.e. this patch.
> +</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>
> diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml
> index d871245..9924732 100644
> --- a/Documentation/DocBook/media/v4l/pixfmt.xml
> +++ b/Documentation/DocBook/media/v4l/pixfmt.xml
> @@ -1620,6 +1620,8 @@ information.</para>
> &sub-y10b;
> &sub-y16;
> &sub-y16-be;
> + &sub-y8i;
> + &sub-y12i;
> &sub-uv8;
> &sub-yuyv;
> &sub-uyvy;
> @@ -1641,6 +1643,14 @@ information.</para>
> &sub-m420;
> </section>
>
> + <section id="depth-formats">
> + <title>Depth Formats</title>
> + <para>Depth data provides distance to points, mapped onto the image plane
> + </para>
> +
> + &sub-z16;
> + </section>
> +
> <section>
> <title>Compressed Formats</title>
>
>
--
Kind regards,
Sakari Ailus
sakari.ailus@linux.intel.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] V4L: add Y12I, Y8I and Z16 pixel format documentation
2016-01-19 13:19 ` Sakari Ailus
@ 2016-01-25 16:15 ` Guennadi Liakhovetski
2016-01-25 17:07 ` Sakari Ailus
0 siblings, 1 reply; 4+ messages in thread
From: Guennadi Liakhovetski @ 2016-01-25 16:15 UTC (permalink / raw)
To: Sakari Ailus
Cc: Linux Media Mailing List, Aviv Greenberg, Hans Verkuil,
Laurent Pinchart
Hi Sakari,
On Tue, 19 Jan 2016, Sakari Ailus wrote:
> Hi Guennadi,
>
> Guennadi Liakhovetski wrote:
> > Add documentation for 3 formats, used by RealSense cameras like R200.
> >
> > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> > ---
[snip]
> > + <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.
>
> I think we really need a way to convey the unit (and prefix) information
> to the user. Considering the same should be done to controls, it'd be
> logical to do that at the same time with the controls.
Do I understand you correctly, that you'd like to add a control to specify
distance units for this format? If yes - I don't think you want a separate
control just for this format, right? And you mention, you also want to be
able to specify units for other controls. But I would've thought, that
controls themselves should define, what unit they are using. E.g.
V4L2_CID_EXPOSURE_ABSOLUTE specifies, that it's unit is 100us. I would
expect the same from other controls too. "Legacy" controls like
V4L2_CID_EXPOSURE don't specify units, so, I would expect, that their use
should be discouraged.
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>
> I'd like to have Hans's and/or Laurent's ack on this as well.
>
> Unless the original patch requires changes, it could be re-applied if no
> changes are requested to it. My understanding is that the issue mainly
> was the missing documentation, i.e. this patch.
Yes, I'll repost both patches as a series, maybe let's try to get some
understanding on the units question first.
Thanks
Guennadi
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] V4L: add Y12I, Y8I and Z16 pixel format documentation
2016-01-25 16:15 ` Guennadi Liakhovetski
@ 2016-01-25 17:07 ` Sakari Ailus
0 siblings, 0 replies; 4+ messages in thread
From: Sakari Ailus @ 2016-01-25 17:07 UTC (permalink / raw)
To: Guennadi Liakhovetski
Cc: Linux Media Mailing List, Aviv Greenberg, Hans Verkuil,
Laurent Pinchart
Hi Guennadi,
Guennadi Liakhovetski wrote:
> Hi Sakari,
>
> On Tue, 19 Jan 2016, Sakari Ailus wrote:
>
>> Hi Guennadi,
>>
>> Guennadi Liakhovetski wrote:
>>> Add documentation for 3 formats, used by RealSense cameras like R200.
>>>
>>> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
>>> ---
>
> [snip]
>
>>> + <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.
>>
>> I think we really need a way to convey the unit (and prefix) information
>> to the user. Considering the same should be done to controls, it'd be
>> logical to do that at the same time with the controls.
>
> Do I understand you correctly, that you'd like to add a control to specify
> distance units for this format? If yes - I don't think you want a separate
> control just for this format, right? And you mention, you also want to be
Considering there are no other depth formats defined, it should be
generic I think, but so far with a single user.
> able to specify units for other controls. But I would've thought, that
> controls themselves should define, what unit they are using. E.g.
> V4L2_CID_EXPOSURE_ABSOLUTE specifies, that it's unit is 100us. I would
> expect the same from other controls too. "Legacy" controls like
> V4L2_CID_EXPOSURE don't specify units, so, I would expect, that their use
> should be discouraged.
Would you create a new control whenever someone needs a new unit for a
control? That's the very problem I think --- currently applications have
no means to know what's the unit for the control.
I've always wondered why we had V4L2_CID_EXPOSURE_ABSOLUTE as
V4L2_CID_EXPOSURE already existed. :-)
The smiapp driver, for instance, uses V4L2_CID_EXPOSURE, and the unit is
lines. There's a fine exposure control as well implemented by many
sensors but the driver currently does not expose that capability.
>> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>>
>> I'd like to have Hans's and/or Laurent's ack on this as well.
>>
>> Unless the original patch requires changes, it could be re-applied if no
>> changes are requested to it. My understanding is that the issue mainly
>> was the missing documentation, i.e. this patch.
>
> Yes, I'll repost both patches as a series, maybe let's try to get some
> understanding on the units question first.
--
Regards,
Sakari Ailus
sakari.ailus@linux.intel.com
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-01-25 17:08 UTC | newest]
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2016-01-18 14:32 [PATCH v2] V4L: add Y12I, Y8I and Z16 pixel format documentation Guennadi Liakhovetski
2016-01-19 13:19 ` Sakari Ailus
2016-01-25 16:15 ` Guennadi Liakhovetski
2016-01-25 17:07 ` Sakari Ailus
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