1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>ioctl VIDIOC_ENUMSTD</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API"><link rel="up" href="user-func.html" title="Appendix A. Function Reference"><link rel="prev" href="vidioc-enumoutput.html" title="ioctl VIDIOC_ENUMOUTPUT"><link rel="next" href="vidioc-expbuf.html" title="ioctl VIDIOC_EXPBUF"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">ioctl VIDIOC_ENUMSTD</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="vidioc-enumoutput.html">Prev</a> </td><th width="60%" align="center">Appendix A. Function Reference</th><td width="20%" align="right"> <a accesskey="n" href="vidioc-expbuf.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="vidioc-enumstd"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>VIDIOC_ENUMSTD — Enumerate supported video standards</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><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_standard *<var class="pdparam">argp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idp1113406756"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>fd</code></em></span></dt><dd><p>File descriptor returned by <a class="link" href="func-open.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_ENUMSTD</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"><a name="idp1113410844"></a><h2>Description</h2><p>To query the attributes of a video standard, 2especially a custom (driver defined) one, applications initialize the 3<em class="structfield"><code>index</code></em> field of struct <a class="link" href="vidioc-enumstd.html#v4l2-standard" title="Table A.46. struct v4l2_standard">v4l2_standard</a> and call the 4<code class="constant">VIDIOC_ENUMSTD</code> ioctl with a pointer to this 5structure. Drivers fill the rest of the structure or return an 6<span class="errorcode">EINVAL</span> error code when the index is out of bounds. To enumerate all standards 7applications shall begin at index zero, incrementing by one until the 8driver returns <span class="errorcode">EINVAL</span>. Drivers may enumerate a 9different set of standards after switching the video input or 10output.<a href="#ftn.idp1113413324" class="footnote" name="idp1113413324"><sup class="footnote">[18]</sup></a></p><div class="table"><a name="v4l2-standard"></a><p class="title"><b>Table A.46. struct <span class="structname">v4l2_standard</span></b></p><div class="table-contents"><table summary="struct v4l2_standard" width="100%" border="0"><colgroup><col class="c1"><col class="c2"><col class="c3"></colgroup><tbody valign="top"><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>index</code></em></td><td valign="top">Number of the video standard, set by the 11application.</td></tr><tr><td valign="top"><a class="link" href="vidioc-enumstd.html#v4l2-std-id" title="Table A.48. typedef v4l2_std_id">v4l2_std_id</a></td><td valign="top"><em class="structfield"><code>id</code></em></td><td valign="top">The bits in this field identify the standard as 12one of the common standards listed in <a class="xref" href="vidioc-enumstd.html#v4l2-std-id" title="Table A.48. typedef v4l2_std_id">Table A.48, “typedef <span class="structname">v4l2_std_id</span>”</a>, 13or if bits 32 to 63 are set as custom standards. Multiple bits can be 14set if the hardware does not distinguish between these standards, 15however separate indices do not indicate the opposite. The 16<em class="structfield"><code>id</code></em> must be unique. No other enumerated 17<span class="structname">v4l2_standard</span> structure, for this input or 18output anyway, can contain the same set of bits.</td></tr><tr><td valign="top">__u8</td><td valign="top"><em class="structfield"><code>name</code></em>[24]</td><td valign="top">Name of the standard, a NUL-terminated ASCII 19string, for example: "PAL-B/G", "NTSC Japan". This information is 20intended for the user.</td></tr><tr><td valign="top">struct <a class="link" href="vidioc-enumstd.html#v4l2-fract" title="Table A.47. struct v4l2_fract">v4l2_fract</a></td><td valign="top"><em class="structfield"><code>frameperiod</code></em></td><td valign="top">The frame period (not field period) is numerator 21/ denominator. For example M/NTSC has a frame period of 1001 / 2230000 seconds.</td></tr><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>framelines</code></em></td><td valign="top">Total lines per frame including blanking, 23e. g. 625 for B/PAL.</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 24the array to zero.</td></tr></tbody></table></div></div><br class="table-break"><div class="table"><a name="v4l2-fract"></a><p class="title"><b>Table A.47. struct <span class="structname">v4l2_fract</span></b></p><div class="table-contents"><table summary="struct v4l2_fract" width="100%" border="0"><colgroup><col class="c1"><col class="c2"><col class="c3"></colgroup><tbody valign="top"><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>numerator</code></em></td><td valign="top"> </td></tr><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>denominator</code></em></td><td valign="top"> </td></tr></tbody></table></div></div><br class="table-break"><div class="table"><a name="v4l2-std-id"></a><p class="title"><b>Table A.48. typedef <span class="structname">v4l2_std_id</span></b></p><div class="table-contents"><table summary="typedef v4l2_std_id" width="100%" border="0"><colgroup><col class="c1"><col class="c2"><col class="c3"></colgroup><tbody valign="top"><tr><td valign="top">__u64</td><td valign="top"><em class="structfield"><code>v4l2_std_id</code></em></td><td valign="top">This type is a set, each bit representing another 25video standard as listed below and in <a class="xref" href="vidioc-enumstd.html#video-standards" title="Table A.49. Video Standards (based on [[ITU BT.470]])">Table A.49, “Video Standards (based on [[<abbr class="abbrev">ITU BT.470</abbr>]])”</a>. The 32 most significant bits are reserved 26for custom (driver defined) video standards.</td></tr></tbody></table></div></div><br class="table-break"><pre class="programlisting"> 27#define V4L2_STD_PAL_B ((v4l2_std_id)0x00000001) 28#define V4L2_STD_PAL_B1 ((v4l2_std_id)0x00000002) 29#define V4L2_STD_PAL_G ((v4l2_std_id)0x00000004) 30#define V4L2_STD_PAL_H ((v4l2_std_id)0x00000008) 31#define V4L2_STD_PAL_I ((v4l2_std_id)0x00000010) 32#define V4L2_STD_PAL_D ((v4l2_std_id)0x00000020) 33#define V4L2_STD_PAL_D1 ((v4l2_std_id)0x00000040) 34#define V4L2_STD_PAL_K ((v4l2_std_id)0x00000080) 35 36#define V4L2_STD_PAL_M ((v4l2_std_id)0x00000100) 37#define V4L2_STD_PAL_N ((v4l2_std_id)0x00000200) 38#define V4L2_STD_PAL_Nc ((v4l2_std_id)0x00000400) 39#define V4L2_STD_PAL_60 ((v4l2_std_id)0x00000800) 40</pre><p><code class="constant">V4L2_STD_PAL_60</code> is 41a hybrid standard with 525 lines, 60 Hz refresh rate, and PAL color 42modulation with a 4.43 MHz color subcarrier. Some PAL video recorders 43can play back NTSC tapes in this mode for display on a 50/60 Hz agnostic 44PAL TV.</p><pre class="programlisting"> 45#define V4L2_STD_NTSC_M ((v4l2_std_id)0x00001000) 46#define V4L2_STD_NTSC_M_JP ((v4l2_std_id)0x00002000) 47#define V4L2_STD_NTSC_443 ((v4l2_std_id)0x00004000) 48</pre><p><code class="constant">V4L2_STD_NTSC_443</code> 49is a hybrid standard with 525 lines, 60 Hz refresh rate, and NTSC 50color modulation with a 4.43 MHz color 51subcarrier.</p><pre class="programlisting"> 52#define V4L2_STD_NTSC_M_KR ((v4l2_std_id)0x00008000) 53 54#define V4L2_STD_SECAM_B ((v4l2_std_id)0x00010000) 55#define V4L2_STD_SECAM_D ((v4l2_std_id)0x00020000) 56#define V4L2_STD_SECAM_G ((v4l2_std_id)0x00040000) 57#define V4L2_STD_SECAM_H ((v4l2_std_id)0x00080000) 58#define V4L2_STD_SECAM_K ((v4l2_std_id)0x00100000) 59#define V4L2_STD_SECAM_K1 ((v4l2_std_id)0x00200000) 60#define V4L2_STD_SECAM_L ((v4l2_std_id)0x00400000) 61#define V4L2_STD_SECAM_LC ((v4l2_std_id)0x00800000) 62 63/* ATSC/HDTV */ 64#define V4L2_STD_ATSC_8_VSB ((v4l2_std_id)0x01000000) 65#define V4L2_STD_ATSC_16_VSB ((v4l2_std_id)0x02000000) 66</pre><p><code class="constant">V4L2_STD_ATSC_8_VSB</code> and 67<code class="constant">V4L2_STD_ATSC_16_VSB</code> are U.S. terrestrial digital 68TV standards. Presently the V4L2 API does not support digital TV. See 69also the Linux DVB API at <a class="ulink" href="http://linuxtv.org" target="_top">http://linuxtv.org</a>.</p><pre class="programlisting"> 70#define V4L2_STD_PAL_BG (V4L2_STD_PAL_B |\ 71 V4L2_STD_PAL_B1 |\ 72 V4L2_STD_PAL_G) 73#define V4L2_STD_B (V4L2_STD_PAL_B |\ 74 V4L2_STD_PAL_B1 |\ 75 V4L2_STD_SECAM_B) 76#define V4L2_STD_GH (V4L2_STD_PAL_G |\ 77 V4L2_STD_PAL_H |\ 78 V4L2_STD_SECAM_G |\ 79 V4L2_STD_SECAM_H) 80#define V4L2_STD_PAL_DK (V4L2_STD_PAL_D |\ 81 V4L2_STD_PAL_D1 |\ 82 V4L2_STD_PAL_K) 83#define V4L2_STD_PAL (V4L2_STD_PAL_BG |\ 84 V4L2_STD_PAL_DK |\ 85 V4L2_STD_PAL_H |\ 86 V4L2_STD_PAL_I) 87#define V4L2_STD_NTSC (V4L2_STD_NTSC_M |\ 88 V4L2_STD_NTSC_M_JP |\ 89 V4L2_STD_NTSC_M_KR) 90#define V4L2_STD_MN (V4L2_STD_PAL_M |\ 91 V4L2_STD_PAL_N |\ 92 V4L2_STD_PAL_Nc |\ 93 V4L2_STD_NTSC) 94#define V4L2_STD_SECAM_DK (V4L2_STD_SECAM_D |\ 95 V4L2_STD_SECAM_K |\ 96 V4L2_STD_SECAM_K1) 97#define V4L2_STD_DK (V4L2_STD_PAL_DK |\ 98 V4L2_STD_SECAM_DK) 99 100#define V4L2_STD_SECAM (V4L2_STD_SECAM_B |\ 101 V4L2_STD_SECAM_G |\ 102 V4L2_STD_SECAM_H |\ 103 V4L2_STD_SECAM_DK |\ 104 V4L2_STD_SECAM_L |\ 105 V4L2_STD_SECAM_LC) 106 107#define V4L2_STD_525_60 (V4L2_STD_PAL_M |\ 108 V4L2_STD_PAL_60 |\ 109 V4L2_STD_NTSC |\ 110 V4L2_STD_NTSC_443) 111#define V4L2_STD_625_50 (V4L2_STD_PAL |\ 112 V4L2_STD_PAL_N |\ 113 V4L2_STD_PAL_Nc |\ 114 V4L2_STD_SECAM) 115 116#define V4L2_STD_UNKNOWN 0 117#define V4L2_STD_ALL (V4L2_STD_525_60 |\ 118 V4L2_STD_625_50) 119</pre><div class="table"><a name="video-standards"></a><p class="title"><b>Table A.49. Video Standards (based on [<a class="xref" href="bi01.html#itu470" title='ITU-R Recommendation BT.470-6 "Conventional Television Systems"'>[<abbr class="abbrev">ITU BT.470</abbr>]</a>])</b></p><div class="table-contents"><table summary="Video Standards (based on [])" width="100%" border="1"><colgroup><col align="left" class="c1"><col align="center" class="c2"><col align="center" class="c3"><col align="center" class="c4"><col align="center" class="c5"><col><col align="center" class="c7"><col><col align="center" class="c9"><col><col><col align="center" class="c12"></colgroup><thead><tr><th align="left">Characteristics</th><th align="center"><p>M/NTSC<a href="#ftn.idp1113450236" class="footnote" name="idp1113450236"><sup class="footnote">[a]</sup></a></p></th><th align="center">M/PAL</th><th align="center"><p>N/PAL<a href="#ftn.idp1113451156" class="footnote" name="idp1113451156"><sup class="footnote">[b]</sup></a></p></th><th align="center">B, B1, G/PAL</th><th align="center">D, D1, K/PAL</th><th align="center">H/PAL</th><th align="center">I/PAL</th><th align="center">B, G/SECAM</th><th align="center">D, K/SECAM</th><th align="center">K1/SECAM</th><th align="center">L/SECAM</th></tr></thead><tbody valign="top"><tr><td align="left" valign="top">Frame lines</td><td colspan="2" align="center" valign="top">525</td><td colspan="9" align="center" valign="top">625</td></tr><tr><td align="left" valign="top">Frame period (s)</td><td colspan="2" align="center" valign="top">1001/30000</td><td colspan="9" align="center" valign="top">1/25</td></tr><tr><td align="left" valign="top">Chrominance sub-carrier frequency (Hz)</td><td align="center" valign="top">3579545 ± 10</td><td align="center" valign="top">3579611.49 ± 10</td><td align="center" valign="top">4433618.75 ± 5 (3582056.25 120± 5)</td><td colspan="3" align="center" valign="top">4433618.75 ± 5</td><td align="center" valign="top">4433618.75 ± 1</td><td colspan="4" align="center" valign="top">f<sub>OR</sub> = 1214406250 ± 2000, f<sub>OB</sub> = 4250000 122± 2000</td></tr><tr><td align="left" valign="top">Nominal radio-frequency channel bandwidth 123(MHz)</td><td align="center" valign="top">6</td><td align="center" valign="top">6</td><td align="center" valign="top">6</td><td align="center" valign="top">B: 7; B1, G: 8</td><td align="center" valign="top">8</td><td align="center" valign="top">8</td><td align="center" valign="top">8</td><td align="center" valign="top">8</td><td align="center" valign="top">8</td><td align="center" valign="top">8</td><td align="center" valign="top">8</td></tr><tr><td align="left" valign="top">Sound carrier relative to vision carrier 124(MHz)</td><td align="center" valign="top">+ 4.5</td><td align="center" valign="top">+ 4.5</td><td align="center" valign="top">+ 4.5</td><td align="center" valign="top"><p>+ 5.5 ± 0.001 125<a href="#ftn.idp1113463516" class="footnote" name="idp1113463516"><sup class="footnote">[c]</sup></a> <a href="#ftn.idp1113463748" class="footnote" name="idp1113463748"><sup class="footnote">[d]</sup></a> <a href="#ftn.idp1113464540" class="footnote" name="idp1113464540"><sup class="footnote">[e]</sup></a> <a href="#ftn.idp1113464732" class="footnote" name="idp1113464732"><sup class="footnote">[f]</sup></a></p></td><td align="center" valign="top">+ 6.5 ± 0.001</td><td align="center" valign="top">+ 5.5</td><td align="center" valign="top">+ 5.9996 ± 0.0005</td><td align="center" valign="top">+ 5.5 ± 0.001</td><td align="center" valign="top">+ 6.5 ± 0.001</td><td align="center" valign="top">+ 6.5</td><td align="center" valign="top"><p>+ 6.5 <a href="#ftn.idp1113466852" class="footnote" name="idp1113466852"><sup class="footnote">[g]</sup></a></p></td></tr></tbody><tbody class="footnotes"><tr><td colspan="12"><div id="ftn.idp1113450236" class="footnote"><p><a href="#idp1113450236" class="para"><sup class="para">[a] </sup></a>Japan uses a standard 126similar to M/NTSC 127(V4L2_STD_NTSC_M_JP).</p></div><div id="ftn.idp1113451156" class="footnote"><p><a href="#idp1113451156" class="para"><sup class="para">[b] </sup></a> The values in 128brackets apply to the combination N/PAL a.k.a. 129N<sub>C</sub> used in Argentina 130(V4L2_STD_PAL_Nc).</p></div><div id="ftn.idp1113463516" class="footnote"><p><a href="#idp1113463516" class="para"><sup class="para">[c] </sup></a>In the Federal Republic of Germany, Austria, Italy, 131the Netherlands, Slovakia and Switzerland a system of two sound 132carriers is used, the frequency of the second carrier being 133242.1875 kHz above the frequency of the first sound carrier. For 134stereophonic sound transmissions a similar system is used in 135Australia.</p></div><div id="ftn.idp1113463748" class="footnote"><p><a href="#idp1113463748" class="para"><sup class="para">[d] </sup></a>New Zealand uses a sound 136carrier displaced 5.4996 ± 0.0005 MHz from the vision 137carrier.</p></div><div id="ftn.idp1113464540" class="footnote"><p><a href="#idp1113464540" class="para"><sup class="para">[e] </sup></a>In Denmark, Finland, New 138Zealand, Sweden and Spain a system of two sound carriers is used. In 139Iceland, Norway and Poland the same system is being introduced. The 140second carrier is 5.85 MHz above the vision carrier and is DQPSK 141modulated with 728 kbit/s sound and data multiplex. (NICAM 142system)</p></div><div id="ftn.idp1113464732" class="footnote"><p><a href="#idp1113464732" class="para"><sup class="para">[f] </sup></a>In the United Kingdom, a 143system of two sound carriers is used. The second sound carrier is 1446.552 MHz above the vision carrier and is DQPSK modulated with a 145728 kbit/s sound and data multiplex able to carry two sound 146channels. (NICAM system)</p></div><div id="ftn.idp1113466852" class="footnote"><p><a href="#idp1113466852" class="para"><sup class="para">[g] </sup></a>In France, a 147digital carrier 5.85 MHz away from the vision carrier may be used in 148addition to the main sound carrier. It is modulated in differentially 149encoded QPSK with a 728 kbit/s sound and data multiplexer capable of 150carrying two sound channels. (NICAM 151system)</p></div></td></tr></tbody></table></div></div><br class="table-break"></div><div class="refsect1"><a name="idp1113467972"></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. The generic error codes are described at the <a class="link" href="gen_errors.html#gen-errors" title="Table 19.1. Generic error codes">Generic Error Codes</a> chapter.</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><span class="errorcode">EINVAL</span></span></dt><dd><p>The struct <a class="link" href="vidioc-enumstd.html#v4l2-standard" title="Table A.46. struct v4l2_standard">v4l2_standard</a> <em class="structfield"><code>index</code></em> 152is out of bounds.</p></dd><dt><span class="term"><span class="errorcode">ENODATA</span></span></dt><dd><p>Standard video timings are not supported for this input or output.</p></dd></dl></div></div><div class="footnotes"><br><hr style="width:100; text-align:left;margin-left: 0"><div id="ftn.idp1113413324" class="footnote"><p><a href="#idp1113413324" class="para"><sup class="para">[18] </sup></a>The supported standards may overlap and we need an 153unambiguous set to find the current standard returned by 154<code class="constant">VIDIOC_G_STD</code>.</p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="vidioc-enumoutput.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="user-func.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="vidioc-expbuf.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ioctl VIDIOC_ENUMOUTPUT </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> ioctl VIDIOC_EXPBUF</td></tr></table></div></body></html> 155