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[media] V4L2 spec: document the new V4L2 DV timings ioctls
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Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Hans Verkuil authored and Mauro Carvalho Chehab committed May 20, 2012
1 parent 06bba75 commit 7dcc606
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18 changes: 18 additions & 0 deletions Documentation/DocBook/media/v4l/biblio.xml
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Expand Up @@ -208,4 +208,22 @@ in the frequency range from 87,5 to 108,0 MHz</title>
recommended exposure index</title>
</biblioentry>

<biblioentry id="cea861">
<abbrev>CEA-861-E</abbrev>
<authorgroup>
<corpauthor>Consumer Electronics Association
(<ulink url="http://www.ce.org">http://www.ce.org</ulink>)</corpauthor>
</authorgroup>
<title>A DTV Profile for Uncompressed High Speed Digital Interfaces</title>
</biblioentry>

<biblioentry id="vesadmt">
<abbrev>VESA&nbsp;DMT</abbrev>
<authorgroup>
<corpauthor>Video Electronics Standards Association
(<ulink url="http://www.vesa.org">http://www.vesa.org</ulink>)</corpauthor>
</authorgroup>
<title>VESA and Industry Standards and Guidelines for Computer Display Monitor Timing (DMT)</title>
</biblioentry>

</bibliography>
32 changes: 19 additions & 13 deletions Documentation/DocBook/media/v4l/common.xml
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Expand Up @@ -724,41 +724,47 @@ if (-1 == ioctl (fd, &VIDIOC-S-STD;, &amp;std_id)) {
}
</programlisting>
</example>
</section>
<section id="dv-timings">
<title>Digital Video (DV) Timings</title>
<para>
The video standards discussed so far has been dealing with Analog TV and the
The video standards discussed so far have been dealing with Analog TV and the
corresponding video timings. Today there are many more different hardware interfaces
such as High Definition TV interfaces (HDMI), VGA, DVI connectors etc., that carry
video signals and there is a need to extend the API to select the video timings
for these interfaces. Since it is not possible to extend the &v4l2-std-id; due to
the limited bits available, a new set of IOCTLs is added to set/get video timings at
the limited bits available, a new set of IOCTLs was added to set/get video timings at
the input and output: </para><itemizedlist>
<listitem>
<para>DV Timings: This will allow applications to define detailed
video timings for the interface. This includes parameters such as width, height,
polarities, frontporch, backporch etc. The <filename>linux/v4l2-dv-timings.h</filename>
header can be used to get the timings of the formats in the <xref linkend="cea861" /> and
<xref linkend="vesadmt" /> standards.
</para>
</listitem>
<listitem>
<para>DV Presets: Digital Video (DV) presets. These are IDs representing a
video timing at the input/output. Presets are pre-defined timings implemented
by the hardware according to video standards. A __u32 data type is used to represent
a preset unlike the bit mask that is used in &v4l2-std-id; allowing future extensions
to support as many different presets as needed.</para>
</listitem>
<listitem>
<para>Custom DV Timings: This will allow applications to define more detailed
custom video timings for the interface. This includes parameters such as width, height,
polarities, frontporch, backporch etc.
</para>
</listitem>
</itemizedlist>
<para>To enumerate and query the attributes of the DV timings supported by a device,
applications use the &VIDIOC-ENUM-DV-TIMINGS; and &VIDIOC-DV-TIMINGS-CAP; ioctls.
To set DV timings for the device, applications use the
&VIDIOC-S-DV-TIMINGS; ioctl and to get current DV timings they use the
&VIDIOC-G-DV-TIMINGS; ioctl. To detect the DV timings as seen by the video receiver applications
use the &VIDIOC-QUERY-DV-TIMINGS; ioctl.</para>
<para>To enumerate and query the attributes of DV presets supported by a device,
applications use the &VIDIOC-ENUM-DV-PRESETS; ioctl. To get the current DV preset,
applications use the &VIDIOC-G-DV-PRESET; ioctl and to set a preset they use the
&VIDIOC-S-DV-PRESET; ioctl.</para>
<para>To set custom DV timings for the device, applications use the
&VIDIOC-S-DV-TIMINGS; ioctl and to get current custom DV timings they use the
&VIDIOC-G-DV-TIMINGS; ioctl.</para>
&VIDIOC-S-DV-PRESET; ioctl. To detect the preset as seen by the video receiver applications
use the &VIDIOC-QUERY-DV-PRESET; ioctl.</para>
<para>Applications can make use of the <xref linkend="input-capabilities" /> and
<xref linkend="output-capabilities"/> flags to decide what ioctls are available to set the
video timings for the device.</para>
</section>
</section>

&sub-controls;
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13 changes: 13 additions & 0 deletions Documentation/DocBook/media/v4l/compat.xml
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Expand Up @@ -2407,6 +2407,11 @@ details.</para>
<para>Added <link linkend="jpeg-controls">JPEG compression control
class</link>.</para>
</listitem>
<listitem>
<para>Extended the DV Timings API:
&VIDIOC-ENUM-DV-TIMINGS;, &VIDIOC-QUERY-DV-TIMINGS; and
&VIDIOC-DV-TIMINGS-CAP;.</para>
</listitem>
</orderedlist>
</section>

Expand Down Expand Up @@ -2548,6 +2553,10 @@ and may change in the future.</para>
</listitem>
<listitem>
<para>&VIDIOC-ENCODER-CMD; and &VIDIOC-TRY-ENCODER-CMD;
ioctls.</para>
</listitem>
<listitem>
<para>&VIDIOC-DECODER-CMD; and &VIDIOC-TRY-DECODER-CMD;
ioctls.</para>
</listitem>
<listitem>
Expand All @@ -2557,6 +2566,10 @@ ioctls.</para>
<listitem>
<para>&VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para>
</listitem>
<listitem>
<para>&VIDIOC-ENUM-DV-TIMINGS;, &VIDIOC-QUERY-DV-TIMINGS; and
&VIDIOC-DV-TIMINGS-CAP; ioctls.</para>
</listitem>
<listitem>
<para>Flash API. <xref linkend="flash-controls" /></para>
</listitem>
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15 changes: 12 additions & 3 deletions Documentation/DocBook/media/v4l/v4l2.xml
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Expand Up @@ -28,8 +28,8 @@ documentation.</contrib>
<firstname>Hans</firstname>
<surname>Verkuil</surname>
<contrib>Designed and documented the VIDIOC_LOG_STATUS ioctl,
the extended control ioctls and major parts of the sliced VBI
API.</contrib>
the extended control ioctls, major parts of the sliced VBI API, the
MPEG encoder and decoder APIs and the DV Timings API.</contrib>
<affiliation>
<address>
<email>hverkuil@xs4all.nl</email>
Expand Down Expand Up @@ -123,6 +123,7 @@ Remote Controller chapter.</contrib>
<year>2009</year>
<year>2010</year>
<year>2011</year>
<year>2012</year>
<holder>Bill Dirks, Michael H. Schimek, Hans Verkuil, Martin
Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab,
Pawel Osciak</holder>
Expand Down Expand Up @@ -153,6 +154,11 @@ applications. -->
V4L2_CID_AUTO_FOCUS_STOP, V4L2_CID_AUTO_FOCUS_STATUS
and V4L2_CID_AUTO_FOCUS_RANGE.
</revremark>
<date>2012-05-01</date>
<authorinitials>hv</authorinitials>
<revremark>Added VIDIOC_ENUM_DV_TIMINGS, VIDIOC_QUERY_DV_TIMINGS and
VIDIOC_DV_TIMINGS_CAP.
</revremark>
</revision>

<revision>
Expand Down Expand Up @@ -461,7 +467,7 @@ and discussions on the V4L mailing list.</revremark>
</partinfo>

<title>Video for Linux Two API Specification</title>
<subtitle>Revision 3.3</subtitle>
<subtitle>Revision 3.5</subtitle>

<chapter id="common">
&sub-common;
Expand Down Expand Up @@ -519,10 +525,12 @@ and discussions on the V4L mailing list.</revremark>
&sub-dbg-g-register;
&sub-decoder-cmd;
&sub-dqevent;
&sub-dv-timings-cap;
&sub-encoder-cmd;
&sub-enumaudio;
&sub-enumaudioout;
&sub-enum-dv-presets;
&sub-enum-dv-timings;
&sub-enum-fmt;
&sub-enum-framesizes;
&sub-enum-frameintervals;
Expand Down Expand Up @@ -557,6 +565,7 @@ and discussions on the V4L mailing list.</revremark>
&sub-querycap;
&sub-queryctrl;
&sub-query-dv-preset;
&sub-query-dv-timings;
&sub-querystd;
&sub-prepare-buf;
&sub-reqbufs;
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6 changes: 6 additions & 0 deletions Documentation/DocBook/media/v4l/vidioc-create-bufs.xml
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Expand Up @@ -48,6 +48,12 @@
<refsect1>
<title>Description</title>

<note>
<title>Experimental</title>
<para>This is an <link linkend="experimental"> experimental </link>
interface and may change in the future.</para>
</note>

<para>This ioctl is used to create buffers for <link linkend="mmap">memory
mapped</link> or <link linkend="userp">user pointer</link>
I/O. It can be used as an alternative or in addition to the
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