<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>ioctl VIDIOC_G_STD, VIDIOC_S_STD</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API" /><link rel="up" href="apa.html" title="Appendix A. Function Reference" /><link rel="prev" href="re49.html" title="ioctl VIDIOC_G_SLICED_VBI_CAP" /><link rel="next" href="re51.html" title="ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">ioctl VIDIOC_G_STD, VIDIOC_S_STD</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re49.html">Prev</a> </td><th width="60%" align="center">Appendix A. Function Reference</th><td width="20%" align="right"> <a accesskey="n" href="re51.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="ioctl VIDIOC_G_STD, VIDIOC_S_STD"><a id="vidioc-g-std"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>VIDIOC_G_STD, VIDIOC_S_STD — Query or select the video standard of the current input</p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">ioctl</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">request</var>, </td></tr><tr><td> </td><td>v4l2_std_id *<var class="pdparam">argp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">ioctl</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">request</var>, </td></tr><tr><td> </td><td>const v4l2_std_id *<var class="pdparam">argp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2724146"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>fd</code></em></span></dt><dd><p>File descriptor returned by <a class="link" href="re64.html" title="V4L2 open()"><code class="function">open()</code></a>.</p></dd><dt><span class="term"><em class="parameter"><code>request</code></em></span></dt><dd><p>VIDIOC_G_STD, VIDIOC_S_STD</p></dd><dt><span class="term"><em class="parameter"><code>argp</code></em></span></dt><dd><p></p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id2724215"></a><h2>Description</h2><p>To query and select the current video standard applications use the <code class="constant">VIDIOC_G_STD</code> and <code class="constant">VIDIOC_S_STD</code> ioctls which take a pointer to a <a class="link" href="re33.html#v4l2-std-id" title="Table A.29. typedef v4l2_std_id">v4l2_std_id</a> type as argument. <code class="constant">VIDIOC_G_STD</code> can return a single flag or a set of flags as in struct <a class="link" href="re33.html#v4l2-standard" title="Table A.27. struct v4l2_standard">v4l2_standard</a> field <em class="structfield"><code>id</code></em>. The flags must be unambiguous such that they appear in only one enumerated <span class="structname">v4l2_standard</span> structure.</p><p><code class="constant">VIDIOC_S_STD</code> accepts one or more flags, being a write-only ioctl it does not return the actual new standard as <code class="constant">VIDIOC_G_STD</code> does. When no flags are given or the current input does not support the requested standard the driver returns an <span class="errorcode">EINVAL</span> error code. When the standard set is ambiguous drivers may return <span class="errorcode">EINVAL</span> or choose any of the requested standards.</p></div><div class="refsect1" title="Return Value"><a id="id2724289"></a><h2>Return Value</h2><p>On success <span class="returnvalue">0</span> is returned, on error <span class="returnvalue">-1</span> and the <code class="varname">errno</code> variable is set appropriately:</p><div class="variablelist"><dl><dt><span class="term"><span class="errorcode">EINVAL</span></span></dt><dd><p>This ioctl is not supported, or the <code class="constant">VIDIOC_S_STD</code> parameter was unsuitable.</p></dd></dl></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re49.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="apa.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re51.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ioctl VIDIOC_G_SLICED_VBI_CAP </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</td></tr></table></div></body></html>
