Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml

   1 <refentry id="vidioc-g-dv-timings">
   2   <refmeta>
   3     <refentrytitle>ioctl VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</refentrytitle>
   4     &manvol;
   5   </refmeta>
   6
   7   <refnamediv>
   8     <refname>VIDIOC_G_DV_TIMINGS</refname>
   9     <refname>VIDIOC_S_DV_TIMINGS</refname>
  10     <refpurpose>Get or set custom DV timings for input or output</refpurpose>
  11   </refnamediv>
  12
  13   <refsynopsisdiv>
  14     <funcsynopsis>
  15       <funcprototype>
  16         <funcdef>int <function>ioctl</function></funcdef>
  17         <paramdef>int <parameter>fd</parameter></paramdef>
  18         <paramdef>int <parameter>request</parameter></paramdef>
  19         <paramdef>struct v4l2_dv_timings *<parameter>argp</parameter></paramdef>
  20       </funcprototype>
  21     </funcsynopsis>
  22   </refsynopsisdiv>
  23
  24   <refsect1>
  25     <title>Arguments</title>
  26
  27     <variablelist>
  28       <varlistentry>
  29         <term><parameter>fd</parameter></term>
  30         <listitem>
  31           <para>&fd;</para>
  32         </listitem>
  33       </varlistentry>
  34       <varlistentry>
  35         <term><parameter>request</parameter></term>
  36         <listitem>
  37           <para>VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS</para>
  38         </listitem>
  39       </varlistentry>
  40       <varlistentry>
  41         <term><parameter>argp</parameter></term>
  42         <listitem>
  43           <para></para>
  44         </listitem>
  45       </varlistentry>
  46     </variablelist>
  47   </refsect1>
  48
  49   <refsect1>
  50     <title>Description</title>
  51     <para>To set custom DV timings for the input or output, applications use the
  52 <constant>VIDIOC_S_DV_TIMINGS</constant> ioctl and to get the current custom timings,
  53 applications use the <constant>VIDIOC_G_DV_TIMINGS</constant> ioctl. The detailed timing
  54 information is filled in using the structure &v4l2-dv-timings;. These ioctls take
  55 a pointer to the &v4l2-dv-timings; structure as argument. If the ioctl is not supported
  56 or the timing values are not correct, the driver returns &EINVAL;.</para>
  57   </refsect1>
  58
  59   <refsect1>
  60     &return-value;
  61
  62     <variablelist>
  63       <varlistentry>
  64         <term><errorcode>EINVAL</errorcode></term>
  65         <listitem>
  66           <para>This ioctl is not supported, or the
  67 <constant>VIDIOC_S_DV_TIMINGS</constant> parameter was unsuitable.</para>
  68         </listitem>
  69       </varlistentry>
  70       <varlistentry>
  71         <term><errorcode>EBUSY</errorcode></term>
  72         <listitem>
  73           <para>The device is busy and therefore can not change the timings.</para>
  74         </listitem>
  75       </varlistentry>
  76     </variablelist>
  77
  78     <table pgwide="1" frame="none" id="v4l2-bt-timings">
  79       <title>struct <structname>v4l2_bt_timings</structname></title>
  80       <tgroup cols="3">
  81         &cs-str;
  82         <tbody valign="top">
  83           <row>
  84             <entry>__u32</entry>
  85             <entry><structfield>width</structfield></entry>
  86             <entry>Width of the active video in pixels</entry>
  87           </row>
  88           <row>
  89             <entry>__u32</entry>
  90             <entry><structfield>height</structfield></entry>
  91             <entry>Height of the active video in lines</entry>
  92           </row>
  93           <row>
  94             <entry>__u32</entry>
  95             <entry><structfield>interlaced</structfield></entry>
  96             <entry>Progressive (0) or interlaced (1)</entry>
  97           </row>
  98           <row>
  99             <entry>__u32</entry>
 100             <entry><structfield>polarities</structfield></entry>
 101             <entry>This is a bit mask that defines polarities of sync signals.
 102 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
 103 (1) it is positive polarity and if is cleared (0), it is negative polarity.</entry>
 104           </row>
 105           <row>
 106             <entry>__u64</entry>
 107             <entry><structfield>pixelclock</structfield></entry>
 108             <entry>Pixel clock in Hz. Ex. 74.25MHz->74250000</entry>
 109           </row>
 110           <row>
 111             <entry>__u32</entry>
 112             <entry><structfield>hfrontporch</structfield></entry>
 113             <entry>Horizontal front porch in pixels</entry>
 114           </row>
 115           <row>
 116             <entry>__u32</entry>
 117             <entry><structfield>hsync</structfield></entry>
 118             <entry>Horizontal sync length in pixels</entry>
 119           </row>
 120           <row>
 121             <entry>__u32</entry>
 122             <entry><structfield>hbackporch</structfield></entry>
 123             <entry>Horizontal back porch in pixels</entry>
 124           </row>
 125           <row>
 126             <entry>__u32</entry>
 127             <entry><structfield>vfrontporch</structfield></entry>
 128             <entry>Vertical front porch in lines</entry>
 129           </row>
 130           <row>
 131             <entry>__u32</entry>
 132             <entry><structfield>vsync</structfield></entry>
 133             <entry>Vertical sync length in lines</entry>
 134           </row>
 135           <row>
 136             <entry>__u32</entry>
 137             <entry><structfield>vbackporch</structfield></entry>
 138             <entry>Vertical back porch in lines</entry>
 139           </row>
 140           <row>
 141             <entry>__u32</entry>
 142             <entry><structfield>il_vfrontporch</structfield></entry>
 143             <entry>Vertical front porch in lines for bottom field of interlaced field formats</entry>
 144           </row>
 145           <row>
 146             <entry>__u32</entry>
 147             <entry><structfield>il_vsync</structfield></entry>
 148             <entry>Vertical sync length in lines for bottom field of interlaced field formats</entry>
 149           </row>
 150           <row>
 151             <entry>__u32</entry>
 152             <entry><structfield>il_vbackporch</structfield></entry>
 153             <entry>Vertical back porch in lines for bottom field of interlaced field formats</entry>
 154           </row>
 155         </tbody>
 156       </tgroup>
 157     </table>
 158
 159     <table pgwide="1" frame="none" id="v4l2-dv-timings">
 160       <title>struct <structname>v4l2_dv_timings</structname></title>
 161       <tgroup cols="4">
 162         &cs-str;
 163         <tbody valign="top">
 164           <row>
 165             <entry>__u32</entry>
 166             <entry><structfield>type</structfield></entry>
 167             <entry></entry>
 168             <entry>Type of DV timings as listed in <xref linkend="dv-timing-types"/>.</entry>
 169           </row>
 170           <row>
 171             <entry>union</entry>
 172             <entry><structfield></structfield></entry>
 173             <entry></entry>
 174           </row>
 175           <row>
 176             <entry></entry>
 177             <entry>&v4l2-bt-timings;</entry>
 178             <entry><structfield>bt</structfield></entry>
 179             <entry>Timings defined by BT.656/1120 specifications</entry>
 180           </row>
 181           <row>
 182             <entry></entry>
 183             <entry>__u32</entry>
 184             <entry><structfield>reserved</structfield>[32]</entry>
 185             <entry></entry>
 186           </row>
 187         </tbody>
 188       </tgroup>
 189     </table>
 190
 191     <table pgwide="1" frame="none" id="dv-timing-types">
 192       <title>DV Timing types</title>
 193       <tgroup cols="3">
 194         &cs-str;
 195         <tbody valign="top">
 196           <row>
 197             <entry>Timing type</entry>
 198             <entry>value</entry>
 199             <entry>Description</entry>
 200           </row>
 201           <row>
 202             <entry></entry>
 203             <entry></entry>
 204             <entry></entry>
 205           </row>
 206           <row>
 207             <entry>V4L2_DV_BT_656_1120</entry>
 208             <entry>0</entry>
 209             <entry>BT.656/1120 timings</entry>
 210           </row>
 211         </tbody>
 212       </tgroup>
 213     </table>
 214   </refsect1>
 215   <refsect1>
 216     &return-value;
 217   </refsect1>
 218 </refentry>