<refentry id="vidioc-g-dv-timings">
  <refmeta>
    <refentrytitle>ioctl VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</refentrytitle>
    &manvol;
  </refmeta>

  <refnamediv>
    <refname>VIDIOC_G_DV_TIMINGS</refname>
    <refname>VIDIOC_S_DV_TIMINGS</refname>
    <refpurpose>Get or set custom DV timings for input or output</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_dv_timings *<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_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><parameter>argp</parameter></term>
	<listitem>
	  <para></para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Description</title>
    <para>To set custom DV timings for the input or output, applications use the
<constant>VIDIOC_S_DV_TIMINGS</constant> ioctl and to get the current custom timings,
applications use the <constant>VIDIOC_G_DV_TIMINGS</constant> ioctl. The detailed timing
information is filled in using the structure &v4l2-dv-timings;. These ioctls take
a pointer to the &v4l2-dv-timings; structure as argument. If the ioctl is not supported
or the timing values are not correct, the driver returns &EINVAL;.</para>
  </refsect1>

  <refsect1>
    &return-value;

    <variablelist>
      <varlistentry>
	<term><errorcode>EINVAL</errorcode></term>
	<listitem>
	  <para>This ioctl is not supported, or the
<constant>VIDIOC_S_DV_TIMINGS</constant> parameter was unsuitable.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><errorcode>EBUSY</errorcode></term>
	<listitem>
	  <para>The device is busy and therefore can not change the timings.</para>
	</listitem>
      </varlistentry>
    </variablelist>

    <table pgwide="1" frame="none" id="v4l2-bt-timings">
      <title>struct <structname>v4l2_bt_timings</structname></title>
      <tgroup cols="3">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>width</structfield></entry>
	    <entry>Width of the active video in pixels</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>height</structfield></entry>
	    <entry>Height of the active video in lines</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>interlaced</structfield></entry>
	    <entry>Progressive (0) or interlaced (1)</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>polarities</structfield></entry>
	    <entry>This is a bit mask that defines polarities of sync signals.
bit 0 (V4L2_DV_VSYNC_POS_POL) is for vertical sync polarity and bit 1 (V4L2_DV_HSYNC_POS_POL) is for horizontal sync polarity. If the bit is set
(1) it is positive polarity and if is cleared (0), it is negative polarity.</entry>
	  </row>
	  <row>
	    <entry>__u64</entry>
	    <entry><structfield>pixelclock</structfield></entry>
	    <entry>Pixel clock in Hz. Ex. 74.25MHz->74250000</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>hfrontporch</structfield></entry>
	    <entry>Horizontal front porch in pixels</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>hsync</structfield></entry>
	    <entry>Horizontal sync length in pixels</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>hbackporch</structfield></entry>
	    <entry>Horizontal back porch in pixels</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>vfrontporch</structfield></entry>
	    <entry>Vertical front porch in lines</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>vsync</structfield></entry>
	    <entry>Vertical sync length in lines</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>vbackporch</structfield></entry>
	    <entry>Vertical back porch in lines</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>il_vfrontporch</structfield></entry>
	    <entry>Vertical front porch in lines for bottom field of interlaced field formats</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>il_vsync</structfield></entry>
	    <entry>Vertical sync length in lines for bottom field of interlaced field formats</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>il_vbackporch</structfield></entry>
	    <entry>Vertical back porch in lines for bottom field of interlaced field formats</entry>
	  </row>
	</tbody>
      </tgroup>
    </table>

    <table pgwide="1" frame="none" id="v4l2-dv-timings">
      <title>struct <structname>v4l2_dv_timings</structname></title>
      <tgroup cols="4">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>type</structfield></entry>
	    <entry></entry>
	    <entry>Type of DV timings as listed in <xref linkend="dv-timing-types"/>.</entry>
	  </row>
	  <row>
	    <entry>union</entry>
	    <entry><structfield></structfield></entry>
	    <entry></entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry>&v4l2-bt-timings;</entry>
	    <entry><structfield>bt</structfield></entry>
	    <entry>Timings defined by BT.656/1120 specifications</entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry>__u32</entry>
	    <entry><structfield>reserved</structfield>[32]</entry>
	    <entry></entry>
	  </row>
	</tbody>
      </tgroup>
    </table>

    <table pgwide="1" frame="none" id="dv-timing-types">
      <title>DV Timing types</title>
      <tgroup cols="3">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>Timing type</entry>
	    <entry>value</entry>
	    <entry>Description</entry>
	  </row>
	  <row>
	    <entry></entry>
	    <entry></entry>
	    <entry></entry>
	  </row>
	  <row>
	    <entry>V4L2_DV_BT_656_1120</entry>
	    <entry>0</entry>
	    <entry>BT.656/1120 timings</entry>
	  </row>
	</tbody>
      </tgroup>
    </table>
  </refsect1>
  <refsect1>
    &return-value;
  </refsect1>
</refentry>
