<?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_ENUMSTD</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="re32.html" title="ioctl VIDIOC_ENUMOUTPUT" /><link rel="next" href="re34.html" title="ioctl VIDIOC_G_AUDIO, VIDIOC_S_AUDIO" /></head><body><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="re32.html">Prev</a> </td><th width="60%" align="center">Appendix A. Function Reference</th><td width="20%" align="right"> <a accesskey="n" href="re34.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="ioctl VIDIOC_ENUMSTD"><a id="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" 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_standard *<var class="pdparam">argp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2700227"></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_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" title="Description"><a id="id2700295"></a><h2>Description</h2><p>To query the attributes of a video standard, especially a custom (driver defined) one, applications initialize the <em class="structfield"><code>index</code></em> field of struct <a class="link" href="re33.html#v4l2-standard" title="Table A.27. struct v4l2_standard">v4l2_standard</a> and call the <code class="constant">VIDIOC_ENUMSTD</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 standards applications shall begin at index zero, incrementing by one until the driver returns <span class="errorcode">EINVAL</span>. Drivers may enumerate a different set of standards after switching the video input or output.<sup>[<a id="id2700339" href="#ftn.id2700339" class="footnote">24</a>]</sup></p><div class="table"><a id="v4l2-standard"></a><p class="title"><b>Table A.27. struct <span class="structname">v4l2_standard</span></b></p><div class="table-contents"><table summary="struct v4l2_standard" 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">Number of the video standard, set by the application.</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>id</code></em></td><td valign="top">The bits in this field identify the standard as one of the common standards listed in <a class="xref" href="re33.html#v4l2-std-id" title="Table A.29. typedef v4l2_std_id">Table A.29, “typedef <span class="structname">v4l2_std_id</span>”</a>, or if bits 32 to 63 are set as custom standards. Multiple bits can be set if the hardware does not distinguish between these standards, however separate indices do not indicate the opposite. The <em class="structfield"><code>id</code></em> must be unique. No other enumerated <span class="structname">v4l2_standard</span> structure, for this input or output 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 string, for example: "PAL-B/G", "NTSC Japan". This information is intended for the user.</td></tr><tr><td valign="top">struct <a class="link" href="re33.html#v4l2-fract" title="Table A.28. 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 / denominator. For example M/NTSC has a frame period of 1001 / 30000 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, e. 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 the array to zero.</td></tr></tbody></table></div></div><br class="table-break" /><div class="table"><a id="v4l2-fract"></a><p class="title"><b>Table A.28. struct <span class="structname">v4l2_fract</span></b></p><div class="table-contents"><table summary="struct v4l2_fract" 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>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 id="v4l2-std-id"></a><p class="title"><b>Table A.29. 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 /><col /><col /></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 video standard as listed below and in <a class="xref" href="re33.html#video-standards" title="Table A.30. Video Standards (based on [[ITU BT.470]])">Table A.30, “Video Standards (based on [[<abbr class="abbrev">ITU BT.470</abbr>]])”</a>. The 32 most significant bits are reserved for custom (driver defined) video standards.</td></tr></tbody></table></div></div><br class="table-break" /><pre class="programlisting"> #define V4L2_STD_PAL_B ((v4l2_std_id)0x00000001) #define V4L2_STD_PAL_B1 ((v4l2_std_id)0x00000002) #define V4L2_STD_PAL_G ((v4l2_std_id)0x00000004) #define V4L2_STD_PAL_H ((v4l2_std_id)0x00000008) #define V4L2_STD_PAL_I ((v4l2_std_id)0x00000010) #define V4L2_STD_PAL_D ((v4l2_std_id)0x00000020) #define V4L2_STD_PAL_D1 ((v4l2_std_id)0x00000040) #define V4L2_STD_PAL_K ((v4l2_std_id)0x00000080) #define V4L2_STD_PAL_M ((v4l2_std_id)0x00000100) #define V4L2_STD_PAL_N ((v4l2_std_id)0x00000200) #define V4L2_STD_PAL_Nc ((v4l2_std_id)0x00000400) #define V4L2_STD_PAL_60 ((v4l2_std_id)0x00000800) </pre><p><code class="constant">V4L2_STD_PAL_60</code> is a hybrid standard with 525 lines, 60 Hz refresh rate, and PAL color modulation with a 4.43 MHz color subcarrier. Some PAL video recorders can play back NTSC tapes in this mode for display on a 50/60 Hz agnostic PAL TV.</p><pre class="programlisting"> #define V4L2_STD_NTSC_M ((v4l2_std_id)0x00001000) #define V4L2_STD_NTSC_M_JP ((v4l2_std_id)0x00002000) #define V4L2_STD_NTSC_443 ((v4l2_std_id)0x00004000) </pre><p><code class="constant">V4L2_STD_NTSC_443</code> is a hybrid standard with 525 lines, 60 Hz refresh rate, and NTSC color modulation with a 4.43 MHz color subcarrier.</p><pre class="programlisting"> #define V4L2_STD_NTSC_M_KR ((v4l2_std_id)0x00008000) #define V4L2_STD_SECAM_B ((v4l2_std_id)0x00010000) #define V4L2_STD_SECAM_D ((v4l2_std_id)0x00020000) #define V4L2_STD_SECAM_G ((v4l2_std_id)0x00040000) #define V4L2_STD_SECAM_H ((v4l2_std_id)0x00080000) #define V4L2_STD_SECAM_K ((v4l2_std_id)0x00100000) #define V4L2_STD_SECAM_K1 ((v4l2_std_id)0x00200000) #define V4L2_STD_SECAM_L ((v4l2_std_id)0x00400000) #define V4L2_STD_SECAM_LC ((v4l2_std_id)0x00800000) /* ATSC/HDTV */ #define V4L2_STD_ATSC_8_VSB ((v4l2_std_id)0x01000000) #define V4L2_STD_ATSC_16_VSB ((v4l2_std_id)0x02000000) </pre><p><code class="constant">V4L2_STD_ATSC_8_VSB</code> and <code class="constant">V4L2_STD_ATSC_16_VSB</code> are U.S. terrestrial digital TV standards. Presently the V4L2 API does not support digital TV. See also the Linux DVB API at <a class="ulink" href="http://linuxtv.org" target="_top">http://linuxtv.org</a>.</p><pre class="programlisting"> #define V4L2_STD_PAL_BG (V4L2_STD_PAL_B |\ V4L2_STD_PAL_B1 |\ V4L2_STD_PAL_G) #define V4L2_STD_B (V4L2_STD_PAL_B |\ V4L2_STD_PAL_B1 |\ V4L2_STD_SECAM_B) #define V4L2_STD_GH (V4L2_STD_PAL_G |\ V4L2_STD_PAL_H |\ V4L2_STD_SECAM_G |\ V4L2_STD_SECAM_H) #define V4L2_STD_PAL_DK (V4L2_STD_PAL_D |\ V4L2_STD_PAL_D1 |\ V4L2_STD_PAL_K) #define V4L2_STD_PAL (V4L2_STD_PAL_BG |\ V4L2_STD_PAL_DK |\ V4L2_STD_PAL_H |\ V4L2_STD_PAL_I) #define V4L2_STD_NTSC (V4L2_STD_NTSC_M |\ V4L2_STD_NTSC_M_JP |\ V4L2_STD_NTSC_M_KR) #define V4L2_STD_MN (V4L2_STD_PAL_M |\ V4L2_STD_PAL_N |\ V4L2_STD_PAL_Nc |\ V4L2_STD_NTSC) #define V4L2_STD_SECAM_DK (V4L2_STD_SECAM_D |\ V4L2_STD_SECAM_K |\ V4L2_STD_SECAM_K1) #define V4L2_STD_DK (V4L2_STD_PAL_DK |\ V4L2_STD_SECAM_DK) #define V4L2_STD_SECAM (V4L2_STD_SECAM_B |\ V4L2_STD_SECAM_G |\ V4L2_STD_SECAM_H |\ V4L2_STD_SECAM_DK |\ V4L2_STD_SECAM_L |\ V4L2_STD_SECAM_LC) #define V4L2_STD_525_60 (V4L2_STD_PAL_M |\ V4L2_STD_PAL_60 |\ V4L2_STD_NTSC |\ V4L2_STD_NTSC_443) #define V4L2_STD_625_50 (V4L2_STD_PAL |\ V4L2_STD_PAL_N |\ V4L2_STD_PAL_Nc |\ V4L2_STD_SECAM) #define V4L2_STD_UNKNOWN 0 #define V4L2_STD_ALL (V4L2_STD_525_60 |\ V4L2_STD_625_50) </pre><div class="table"><a id="video-standards"></a><p class="title"><b>Table A.30. 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" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col /><col align="center" /><col /><col align="center" /><col /><col /><col align="center" /></colgroup><thead><tr><th align="left">Characteristics</th><th align="center"><p>M/NTSC<sup>[<a id="id2700952" href="#ftn.id2700952" class="footnote">a</a>]</sup></p></th><th align="center">M/PAL</th><th align="center"><p>N/PAL<sup>[<a id="id2700967" href="#ftn.id2700967" class="footnote">b</a>]</sup></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 ± 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> = 4406250 ± 2000, f<sub>OB</sub> = 4250000 ± 2000</td></tr><tr><td align="left" valign="top">Nominal radio-frequency channel bandwidth (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 (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 <sup>[<a id="id2701171" href="#ftn.id2701171" class="footnote">c</a>]</sup> <sup>[<a id="id2701175" href="#ftn.id2701175" class="footnote">d</a>]</sup> <sup>[<a id="id2701188" href="#ftn.id2701188" class="footnote">e</a>]</sup> <sup>[<a id="id2701191" href="#ftn.id2701191" class="footnote">f</a>]</sup></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 <sup>[<a id="id2701226" href="#ftn.id2701226" class="footnote">g</a>]</sup></p></td></tr></tbody><tbody class="footnotes"><tr><td colspan="12"><div class="footnote"><p><sup>[<a id="ftn.id2700952" href="#id2700952" class="para">a</a>] </sup>Japan uses a standard similar to M/NTSC (V4L2_STD_NTSC_M_JP).</p></div><div class="footnote"><p><sup>[<a id="ftn.id2700967" href="#id2700967" class="para">b</a>] </sup> The values in brackets apply to the combination N/PAL a.k.a. N<sub>C</sub> used in Argentina (V4L2_STD_PAL_Nc).</p></div><div class="footnote"><p><sup>[<a id="ftn.id2701171" href="#id2701171" class="para">c</a>] </sup>In the Federal Republic of Germany, Austria, Italy, the Netherlands, Slovakia and Switzerland a system of two sound carriers is used, the frequency of the second carrier being 242.1875 kHz above the frequency of the first sound carrier. For stereophonic sound transmissions a similar system is used in Australia.</p></div><div class="footnote"><p><sup>[<a id="ftn.id2701175" href="#id2701175" class="para">d</a>] </sup>New Zealand uses a sound carrier displaced 5.4996 ± 0.0005 MHz from the vision carrier.</p></div><div class="footnote"><p><sup>[<a id="ftn.id2701188" href="#id2701188" class="para">e</a>] </sup>In Denmark, Finland, New Zealand, Sweden and Spain a system of two sound carriers is used. In Iceland, Norway and Poland the same system is being introduced. The second carrier is 5.85 MHz above the vision carrier and is DQPSK modulated with 728 kbit/s sound and data multiplex. (NICAM system)</p></div><div class="footnote"><p><sup>[<a id="ftn.id2701191" href="#id2701191" class="para">f</a>] </sup>In the United Kingdom, a system of two sound carriers is used. The second sound carrier is 6.552 MHz above the vision carrier and is DQPSK modulated with a 728 kbit/s sound and data multiplex able to carry two sound channels. (NICAM system)</p></div><div class="footnote"><p><sup>[<a id="ftn.id2701226" href="#id2701226" class="para">g</a>] </sup>In France, a digital carrier 5.85 MHz away from the vision carrier may be used in addition to the main sound carrier. It is modulated in differentially encoded QPSK with a 728 kbit/s sound and data multiplexer capable of carrying two sound channels. (NICAM system)</p></div></td></tr></tbody></table></div></div><br class="table-break" /></div><div class="refsect1" title="Return Value"><a id="id2701245"></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="re33.html#v4l2-standard" title="Table A.27. struct v4l2_standard">v4l2_standard</a> <em class="structfield"><code>index</code></em> is out of bounds.</p></dd></dl></div></div><div class="footnotes"><br /><hr width="100" align="left" /><div class="footnote"><p><sup>[<a id="ftn.id2700339" href="#id2700339" class="para">24</a>] </sup>The supported standards may overlap and we need an unambiguous set to find the current standard returned by <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="re32.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="re34.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_G_AUDIO, VIDIOC_S_AUDIO</td></tr></table></div></body></html>
