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Diffstat (limited to 'kernel/Documentation/DocBook/media/v4l/selections-common.xml')
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diff --git a/kernel/Documentation/DocBook/media/v4l/selections-common.xml b/kernel/Documentation/DocBook/media/v4l/selections-common.xml new file mode 100644 index 000000000..d6d56fb6f --- /dev/null +++ b/kernel/Documentation/DocBook/media/v4l/selections-common.xml @@ -0,0 +1,180 @@ +<section id="v4l2-selections-common"> + + <title>Common selection definitions</title> + + <para>While the <link linkend="selection-api">V4L2 selection + API</link> and <link linkend="v4l2-subdev-selections">V4L2 subdev + selection APIs</link> are very similar, there's one fundamental + difference between the two. On sub-device API, the selection + rectangle refers to the media bus format, and is bound to a + sub-device's pad. On the V4L2 interface the selection rectangles + refer to the in-memory pixel format.</para> + + <para>This section defines the common definitions of the + selection interfaces on the two APIs.</para> + + <section id="v4l2-selection-targets"> + + <title>Selection targets</title> + + <para>The precise meaning of the selection targets may be + dependent on which of the two interfaces they are used.</para> + + <table pgwide="1" frame="none" id="v4l2-selection-targets-table"> + <title>Selection target definitions</title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + &cs-def; + <thead> + <row rowsep="1"> + <entry align="left">Target name</entry> + <entry align="left">id</entry> + <entry align="left">Definition</entry> + <entry align="left">Valid for V4L2</entry> + <entry align="left">Valid for V4L2 subdev</entry> + </row> + </thead> + <tbody valign="top"> + <row> + <entry><constant>V4L2_SEL_TGT_CROP</constant></entry> + <entry>0x0000</entry> + <entry>Crop rectangle. Defines the cropped area.</entry> + <entry>Yes</entry> + <entry>Yes</entry> + </row> + <row> + <entry><constant>V4L2_SEL_TGT_CROP_DEFAULT</constant></entry> + <entry>0x0001</entry> + <entry>Suggested cropping rectangle that covers the "whole picture".</entry> + <entry>Yes</entry> + <entry>No</entry> + </row> + <row> + <entry><constant>V4L2_SEL_TGT_CROP_BOUNDS</constant></entry> + <entry>0x0002</entry> + <entry>Bounds of the crop rectangle. All valid crop + rectangles fit inside the crop bounds rectangle. + </entry> + <entry>Yes</entry> + <entry>Yes</entry> + </row> + <row> + <entry><constant>V4L2_SEL_TGT_NATIVE_SIZE</constant></entry> + <entry>0x0003</entry> + <entry>The native size of the device, e.g. a sensor's + pixel array. <structfield>left</structfield> and + <structfield>top</structfield> fields are zero for this + target. Setting the native size will generally only make + sense for memory to memory devices where the software can + create a canvas of a given size in which for example a + video frame can be composed. In that case + V4L2_SEL_TGT_NATIVE_SIZE can be used to configure the size + of that canvas. + </entry> + <entry>Yes</entry> + <entry>Yes</entry> + </row> + <row> + <entry><constant>V4L2_SEL_TGT_COMPOSE</constant></entry> + <entry>0x0100</entry> + <entry>Compose rectangle. Used to configure scaling + and composition.</entry> + <entry>Yes</entry> + <entry>Yes</entry> + </row> + <row> + <entry><constant>V4L2_SEL_TGT_COMPOSE_DEFAULT</constant></entry> + <entry>0x0101</entry> + <entry>Suggested composition rectangle that covers the "whole picture".</entry> + <entry>Yes</entry> + <entry>No</entry> + </row> + <row> + <entry><constant>V4L2_SEL_TGT_COMPOSE_BOUNDS</constant></entry> + <entry>0x0102</entry> + <entry>Bounds of the compose rectangle. All valid compose + rectangles fit inside the compose bounds rectangle.</entry> + <entry>Yes</entry> + <entry>Yes</entry> + </row> + <row> + <entry><constant>V4L2_SEL_TGT_COMPOSE_PADDED</constant></entry> + <entry>0x0103</entry> + <entry>The active area and all padding pixels that are inserted or + modified by hardware.</entry> + <entry>Yes</entry> + <entry>No</entry> + </row> + </tbody> + </tgroup> + </table> + + </section> + + <section id="v4l2-selection-flags"> + + <title>Selection flags</title> + + <table pgwide="1" frame="none" id="v4l2-selection-flags-table"> + <title>Selection flag definitions</title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + &cs-def; + <thead> + <row rowsep="1"> + <entry align="left">Flag name</entry> + <entry align="left">id</entry> + <entry align="left">Definition</entry> + <entry align="left">Valid for V4L2</entry> + <entry align="left">Valid for V4L2 subdev</entry> + </row> + </thead> + <tbody valign="top"> + <row> + <entry><constant>V4L2_SEL_FLAG_GE</constant></entry> + <entry>(1 << 0)</entry> + <entry>Suggest the driver it should choose greater or + equal rectangle (in size) than was requested. Albeit the + driver may choose a lesser size, it will only do so due to + hardware limitations. Without this flag (and + <constant>V4L2_SEL_FLAG_LE</constant>) the + behaviour is to choose the closest possible + rectangle.</entry> + <entry>Yes</entry> + <entry>Yes</entry> + </row> + <row> + <entry><constant>V4L2_SEL_FLAG_LE</constant></entry> + <entry>(1 << 1)</entry> + <entry>Suggest the driver it + should choose lesser or equal rectangle (in size) than was + requested. Albeit the driver may choose a greater size, it + will only do so due to hardware limitations.</entry> + <entry>Yes</entry> + <entry>Yes</entry> + </row> + <row> + <entry><constant>V4L2_SEL_FLAG_KEEP_CONFIG</constant></entry> + <entry>(1 << 2)</entry> + <entry>The configuration must not be propagated to any + further processing steps. If this flag is not given, the + configuration is propagated inside the subdevice to all + further processing steps.</entry> + <entry>No</entry> + <entry>Yes</entry> + </row> + </tbody> + </tgroup> + </table> + + </section> + +</section> |