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Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-enum-frameintervals.xml')
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diff --git a/Documentation/DocBook/media/v4l/vidioc-enum-frameintervals.xml b/Documentation/DocBook/media/v4l/vidioc-enum-frameintervals.xml deleted file mode 100644 index 7c839ab0a..000000000 --- a/Documentation/DocBook/media/v4l/vidioc-enum-frameintervals.xml +++ /dev/null @@ -1,260 +0,0 @@ -<refentry id="vidioc-enum-frameintervals"> - - <refmeta> - <refentrytitle>ioctl VIDIOC_ENUM_FRAMEINTERVALS</refentrytitle> - &manvol; - </refmeta> - - <refnamediv> - <refname>VIDIOC_ENUM_FRAMEINTERVALS</refname> - <refpurpose>Enumerate frame intervals</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcprototype> - <funcdef>int <function>ioctl</function></funcdef> - <paramdef>int <parameter>fd</parameter></paramdef> - <paramdef>int <parameter>request</parameter></paramdef> - <paramdef>struct v4l2_frmivalenum *<parameter>argp</parameter></paramdef> - </funcprototype> - </funcsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Arguments</title> - - <variablelist> - <varlistentry> - <term><parameter>fd</parameter></term> - <listitem> - <para>&fd;</para> - </listitem> - </varlistentry> - <varlistentry> - <term><parameter>request</parameter></term> - <listitem> - <para>VIDIOC_ENUM_FRAMEINTERVALS</para> - </listitem> - </varlistentry> - <varlistentry> - <term><parameter>argp</parameter></term> - <listitem> - <para>Pointer to a &v4l2-frmivalenum; structure that -contains a pixel format and size and receives a frame interval.</para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>Description</title> - - <para>This ioctl allows applications to enumerate all frame -intervals that the device supports for the given pixel format and -frame size.</para> - <para>The supported pixel formats and frame sizes can be obtained -by using the &VIDIOC-ENUM-FMT; and &VIDIOC-ENUM-FRAMESIZES; -functions.</para> - <para>The return value and the content of the -<structfield>v4l2_frmivalenum.type</structfield> field depend on the -type of frame intervals the device supports. Here are the semantics of -the function for the different cases:</para> - <itemizedlist> - <listitem> - <para><emphasis role="bold">Discrete:</emphasis> The function -returns success if the given index value (zero-based) is valid. The -application should increase the index by one for each call until -<constant>EINVAL</constant> is returned. The `v4l2_frmivalenum.type` -field is set to `V4L2_FRMIVAL_TYPE_DISCRETE` by the driver. Of the -union only the `discrete` member is valid.</para> - </listitem> - <listitem> - <para><emphasis role="bold">Step-wise:</emphasis> The function -returns success if the given index value is zero and -<constant>EINVAL</constant> for any other index value. The -<structfield>v4l2_frmivalenum.type</structfield> field is set to -<constant>V4L2_FRMIVAL_TYPE_STEPWISE</constant> by the driver. Of the -union only the <structfield>stepwise</structfield> member is -valid.</para> - </listitem> - <listitem> - <para><emphasis role="bold">Continuous:</emphasis> This is a -special case of the step-wise type above. The function returns success -if the given index value is zero and <constant>EINVAL</constant> for -any other index value. The -<structfield>v4l2_frmivalenum.type</structfield> field is set to -<constant>V4L2_FRMIVAL_TYPE_CONTINUOUS</constant> by the driver. Of -the union only the <structfield>stepwise</structfield> member is valid -and the <structfield>step</structfield> value is set to 1.</para> - </listitem> - </itemizedlist> - - <para>When the application calls the function with index zero, it -must check the <structfield>type</structfield> field to determine the -type of frame interval enumeration the device supports. Only for the -<constant>V4L2_FRMIVAL_TYPE_DISCRETE</constant> type does it make -sense to increase the index value to receive more frame -intervals.</para> - <para>Note that the order in which the frame intervals are -returned has no special meaning. In particular does it not say -anything about potential default frame intervals.</para> - <para>Applications can assume that the enumeration data does not -change without any interaction from the application itself. This means -that the enumeration data is consistent if the application does not -perform any other ioctl calls while it runs the frame interval -enumeration.</para> - </refsect1> - - <refsect1> - <title>Notes</title> - - <itemizedlist> - <listitem> - <para><emphasis role="bold">Frame intervals and frame -rates:</emphasis> The V4L2 API uses frame intervals instead of frame -rates. Given the frame interval the frame rate can be computed as -follows:<screen>frame_rate = 1 / frame_interval</screen></para> - </listitem> - </itemizedlist> - - </refsect1> - - <refsect1> - <title>Structs</title> - - <para>In the structs below, <emphasis>IN</emphasis> denotes a -value that has to be filled in by the application, -<emphasis>OUT</emphasis> denotes values that the driver fills in. The -application should zero out all members except for the -<emphasis>IN</emphasis> fields.</para> - - <table pgwide="1" frame="none" id="v4l2-frmival-stepwise"> - <title>struct <structname>v4l2_frmival_stepwise</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>&v4l2-fract;</entry> - <entry><structfield>min</structfield></entry> - <entry>Minimum frame interval [s].</entry> - </row> - <row> - <entry>&v4l2-fract;</entry> - <entry><structfield>max</structfield></entry> - <entry>Maximum frame interval [s].</entry> - </row> - <row> - <entry>&v4l2-fract;</entry> - <entry><structfield>step</structfield></entry> - <entry>Frame interval step size [s].</entry> - </row> - </tbody> - </tgroup> - </table> - - <table pgwide="1" frame="none" id="v4l2-frmivalenum"> - <title>struct <structname>v4l2_frmivalenum</structname></title> - <tgroup cols="4"> - <colspec colname="c1" /> - <colspec colname="c2" /> - <colspec colname="c3" /> - <colspec colname="c4" /> - <tbody valign="top"> - <row> - <entry>__u32</entry> - <entry><structfield>index</structfield></entry> - <entry></entry> - <entry>IN: Index of the given frame interval in the -enumeration.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>pixel_format</structfield></entry> - <entry></entry> - <entry>IN: Pixel format for which the frame intervals are -enumerated.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>width</structfield></entry> - <entry></entry> - <entry>IN: Frame width for which the frame intervals are -enumerated.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>height</structfield></entry> - <entry></entry> - <entry>IN: Frame height for which the frame intervals are -enumerated.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>type</structfield></entry> - <entry></entry> - <entry>OUT: Frame interval type the device supports.</entry> - </row> - <row> - <entry>union</entry> - <entry></entry> - <entry></entry> - <entry>OUT: Frame interval with the given index.</entry> - </row> - <row> - <entry></entry> - <entry>&v4l2-fract;</entry> - <entry><structfield>discrete</structfield></entry> - <entry>Frame interval [s].</entry> - </row> - <row> - <entry></entry> - <entry>&v4l2-frmival-stepwise;</entry> - <entry><structfield>stepwise</structfield></entry> - <entry></entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>reserved[2]</structfield></entry> - <entry></entry> - <entry>Reserved space for future use. Must be zeroed by drivers and - applications.</entry> - </row> - </tbody> - </tgroup> - </table> - </refsect1> - - <refsect1> - <title>Enums</title> - - <table pgwide="1" frame="none" id="v4l2-frmivaltypes"> - <title>enum <structname>v4l2_frmivaltypes</structname></title> - <tgroup cols="3"> - &cs-def; - <tbody valign="top"> - <row> - <entry><constant>V4L2_FRMIVAL_TYPE_DISCRETE</constant></entry> - <entry>1</entry> - <entry>Discrete frame interval.</entry> - </row> - <row> - <entry><constant>V4L2_FRMIVAL_TYPE_CONTINUOUS</constant></entry> - <entry>2</entry> - <entry>Continuous frame interval.</entry> - </row> - <row> - <entry><constant>V4L2_FRMIVAL_TYPE_STEPWISE</constant></entry> - <entry>3</entry> - <entry>Step-wise defined frame interval.</entry> - </row> - </tbody> - </tgroup> - </table> - </refsect1> - - <refsect1> - &return-value; - </refsect1> - -</refentry> |