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