<?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_ENUMOUTPUT</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="re31.html" title="ioctl VIDIOC_ENUMINPUT" /><link rel="next" href="re33.html" title="ioctl VIDIOC_ENUMSTD" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">ioctl VIDIOC_ENUMOUTPUT</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re31.html">Prev</a> </td><th width="60%" align="center">Appendix A. Function Reference</th><td width="20%" align="right"> <a accesskey="n" href="re33.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="ioctl VIDIOC_ENUMOUTPUT"><a id="vidioc-enumoutput"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>VIDIOC_ENUMOUTPUT — Enumerate video outputs</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>struct v4l2_output *<var class="pdparam">argp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2699075"></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_ENUMOUTPUT</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="id2699143"></a><h2>Description</h2><p>To query the attributes of a video outputs applications initialize the <em class="structfield"><code>index</code></em> field of struct <a class="link" href="re32.html#v4l2-output" title="Table A.25. struct v4l2_output">v4l2_output</a> and call the <code class="constant">VIDIOC_ENUMOUTPUT</code> ioctl with a pointer to this structure. Drivers fill the rest of the structure or return an <span class="errorcode">EINVAL</span> error code when the index is out of bounds. To enumerate all outputs applications shall begin at index zero, incrementing by one until the driver returns <span class="errorcode">EINVAL</span>.</p><div class="table"><a id="v4l2-output"></a><p class="title"><b>Table A.25. struct <span class="structname">v4l2_output</span></b></p><div class="table-contents"><table summary="struct v4l2_output" width="100%" border="0"><colgroup><col /><col /><col /></colgroup><tbody valign="top"><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>index</code></em></td><td valign="top">Identifies the output, set by the application.</td></tr><tr><td valign="top">__u8</td><td valign="top"><em class="structfield"><code>name</code></em>[32]</td><td valign="top">Name of the video output, a NUL-terminated ASCII string, for example: "Vout". This information is intended for the user, preferably the connector label on the device itself.</td></tr><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>type</code></em></td><td valign="top">Type of the output, see <a class="xref" href="re32.html#output-type" title="Table A.26. Output Type">Table A.26, “Output Type”</a>.</td></tr><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>audioset</code></em></td><td valign="top"><p>Drivers can enumerate up to 32 video and audio outputs. This field shows which audio outputs were selectable as the current output if this was the currently selected video output. It is a bit mask. The LSB corresponds to audio output 0, the MSB to output 31. Any number of bits can be set, or none.</p><p>When the driver does not enumerate audio outputs no bits must be set. Applications shall not interpret this as lack of audio support. Drivers may automatically select audio outputs without enumerating them.</p><p>For details on audio outputs and how to select the current output see <a class="xref" href="ch01s05.html" title="Audio Inputs and Outputs">the section called “Audio Inputs and Outputs”</a>.</p></td></tr><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>modulator</code></em></td><td valign="top">Output devices can have zero or more RF modulators. When the <em class="structfield"><code>type</code></em> is <code class="constant">V4L2_OUTPUT_TYPE_MODULATOR</code> this is an RF connector and this field identifies the modulator. It corresponds to struct <a class="link" href="re45.html#v4l2-modulator" title="Table A.50. struct v4l2_modulator">v4l2_modulator</a> field <em class="structfield"><code>index</code></em>. For details on modulators see <a class="xref" href="ch01s06.html" title="Tuners and Modulators">the section called “Tuners and Modulators”</a>.</td></tr><tr><td valign="top"><a class="link" href="re33.html#v4l2-std-id" title="Table A.29. typedef v4l2_std_id">v4l2_std_id</a></td><td valign="top"><em class="structfield"><code>std</code></em></td><td valign="top">Every video output supports one or more different video standards. This field is a set of all supported standards. For details on video standards and how to switch see <a class="xref" href="ch01s07.html" title="Video Standards">the section called “Video Standards”</a>.</td></tr><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>reserved</code></em>[4]</td><td valign="top">Reserved for future extensions. Drivers must set the array to zero.</td></tr></tbody></table></div></div><br class="table-break" /><div class="table"><a id="output-type"></a><p class="title"><b>Table A.26. Output Type</b></p><div class="table-contents"><table summary="Output Type" width="100%" border="0"><colgroup><col /><col /><col /></colgroup><tbody valign="top"><tr><td valign="top"><code class="constant">V4L2_OUTPUT_TYPE_MODULATOR</code></td><td valign="top">1</td><td valign="top">This output is an analog TV modulator.</td></tr><tr><td valign="top"><code class="constant">V4L2_OUTPUT_TYPE_ANALOG</code></td><td valign="top">2</td><td valign="top">Analog baseband output, for example Composite / CVBS, S-Video, RGB.</td></tr><tr><td valign="top"><code class="constant">V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY</code></td><td valign="top">3</td><td valign="top">[?]</td></tr></tbody></table></div></div><br class="table-break" /></div><div class="refsect1" title="Return Value"><a id="id2699510"></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>The struct <a class="link" href="re32.html#v4l2-output" title="Table A.25. struct v4l2_output">v4l2_output</a> <em class="structfield"><code>index</code></em> is out of bounds.</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="re31.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="re33.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ioctl VIDIOC_ENUMINPUT </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> ioctl VIDIOC_ENUMSTD</td></tr></table></div></body></html>
