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<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_SLICED_VBI_CAP</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="re48.html" title="ioctl VIDIOC_G_PRIORITY, VIDIOC_S_PRIORITY" /><link rel="next" href="re50.html" title="ioctl VIDIOC_G_STD, VIDIOC_S_STD" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">ioctl VIDIOC_G_SLICED_VBI_CAP</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re48.html">Prev</a> </td><th width="60%" align="center">Appendix A. Function Reference</th><td width="20%" align="right"> <a accesskey="n" href="re50.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="ioctl VIDIOC_G_SLICED_VBI_CAP"><a id="vidioc-g-sliced-vbi-cap"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>VIDIOC_G_SLICED_VBI_CAP — Query sliced VBI capabilities</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_sliced_vbi_cap *<var class="pdparam">argp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2911473"></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_SLICED_VBI_CAP</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="id2912491"></a><h2>Description</h2><p>To find out which data services are supported by a sliced
VBI capture or output device, applications initialize the
<em class="structfield"><code>type</code></em> field of a struct <a class="link" href="re49.html#v4l2-sliced-vbi-cap" title="Table A.58. struct v4l2_sliced_vbi_cap">v4l2_sliced_vbi_cap</a>,
clear the <em class="structfield"><code>reserved</code></em> array and
call the <code class="constant">VIDIOC_G_SLICED_VBI_CAP</code> ioctl. The
driver fills in the remaining fields or returns an <span class="errorcode">EINVAL</span> error code if the
sliced VBI API is unsupported or <em class="structfield"><code>type</code></em>
is invalid.</p><p>Note the <em class="structfield"><code>type</code></em> field was added,
and the ioctl changed from read-only to write-read, in Linux 2.6.19.</p><div class="table"><a id="v4l2-sliced-vbi-cap"></a><p class="title"><b>Table A.58. struct <span class="structname">v4l2_sliced_vbi_cap</span></b></p><div class="table-contents"><table summary="struct v4l2_sliced_vbi_cap" width="100%" border="0"><colgroup><col /><col /><col /><col /><col /></colgroup><tbody valign="top"><tr><td valign="top">__u16</td><td valign="top"><em class="structfield"><code>service_set</code></em></td><td colspan="3" valign="top">A set of all data services
supported by the driver. Equal to the union of all elements of the
<em class="structfield"><code>service_lines </code></em> array.</td></tr><tr><td valign="top">__u16</td><td valign="top"><em class="structfield"><code>service_lines</code></em>[2][24]</td><td colspan="3" valign="top">Each element of this array
contains a set of data services the hardware can look for or insert
into a particular scan line. Data services are defined in <a class="xref" href="re49.html#vbi-services" title="Table A.59. Sliced VBI services">Table A.59, “Sliced VBI services”</a>. Array indices map to ITU-R
line numbers (see also <a class="xref" href="ch04s07.html#vbi-525" title="Figure 4.2. ITU-R 525 line numbering (M/NTSC and M/PAL)">Figure 4.2, “ITU-R 525 line numbering (M/NTSC and M/PAL)”</a> and <a class="xref" href="ch04s07.html#vbi-625" title="Figure 4.3. ITU-R 625 line numbering">Figure 4.3, “ITU-R 625 line numbering”</a>) as follows:</td></tr><tr><td valign="top"> </td><td valign="top"> </td><td valign="top">Element</td><td valign="top">525 line systems</td><td valign="top">625 line systems</td></tr><tr><td valign="top"> </td><td valign="top"> </td><td valign="top"><em class="structfield"><code>service_lines</code></em>[0][1]</td><td align="center" valign="top">1</td><td align="center" valign="top">1</td></tr><tr><td valign="top"> </td><td valign="top"> </td><td valign="top"><em class="structfield"><code>service_lines</code></em>[0][23]</td><td align="center" valign="top">23</td><td align="center" valign="top">23</td></tr><tr><td valign="top"> </td><td valign="top"> </td><td valign="top"><em class="structfield"><code>service_lines</code></em>[1][1]</td><td align="center" valign="top">264</td><td align="center" valign="top">314</td></tr><tr><td valign="top"> </td><td valign="top"> </td><td valign="top"><em class="structfield"><code>service_lines</code></em>[1][23]</td><td align="center" valign="top">286</td><td align="center" valign="top">336</td></tr><tr><td valign="top"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr><tr><td valign="top"> </td><td valign="top"> </td><td colspan="3" valign="top">The number of VBI lines the
hardware can capture or output per frame, or the number of services it
can identify on a given line may be limited. For example on PAL line
16 the hardware may be able to look for a VPS or Teletext signal, but
not both at the same time. Applications can learn about these limits
using the <a class="link" href="re41.html" title="ioctl VIDIOC_G_FMT, VIDIOC_S_FMT, VIDIOC_TRY_FMT"><code class="constant">VIDIOC_S_FMT</code></a> ioctl as described in <a class="xref" href="ch04s08.html" title="Sliced VBI Data Interface">the section called “Sliced VBI Data Interface”</a>.</td></tr><tr><td valign="top"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr><tr><td valign="top"> </td><td valign="top"> </td><td colspan="3" valign="top">Drivers must set
<em class="structfield"><code>service_lines</code></em>[0][0] and
<em class="structfield"><code>service_lines</code></em>[1][0] to zero.</td></tr><tr><td valign="top">enum <a class="link" href="ch03s05.html#v4l2-buf-type" title="Table 3.2. enum v4l2_buf_type">v4l2_buf_type</a></td><td valign="top"><em class="structfield"><code>type</code></em></td><td valign="top">Type of the data stream, see <a class="xref" href="ch03s05.html#v4l2-buf-type" title="Table 3.2. enum v4l2_buf_type">Table 3.2, “enum v4l2_buf_type”</a>. Should be
<code class="constant">V4L2_BUF_TYPE_SLICED_VBI_CAPTURE</code> or
<code class="constant">V4L2_BUF_TYPE_SLICED_VBI_OUTPUT</code>.</td><td class="auto-generated"> </td><td class="auto-generated"> </td></tr><tr><td valign="top">__u32</td><td valign="top"><em class="structfield"><code>reserved</code></em>[3]</td><td colspan="3" valign="top">This array is reserved for future
extensions. Applications and drivers must set it to zero.</td></tr></tbody></table></div></div><br class="table-break" /><div class="table"><a id="vbi-services"></a><p class="title"><b>Table A.59. Sliced VBI services</b></p><div class="table-contents"><table summary="Sliced VBI services" width="100%" border="0"><colgroup><col /><col /><col /><col /><col /></colgroup><thead><tr><th>Symbol</th><th>Value</th><th>Reference</th><th>Lines, usually</th><th>Payload</th></tr></thead><tbody valign="top"><tr><td valign="top"><code class="constant">V4L2_SLICED_TELETEXT_B</code> (Teletext
System B)</td><td valign="top">0x0001</td><td valign="top"><a class="xref" href="bi01.html#ets300706" title="ETS 300 706 "Enhanced Teletext specification"">[<abbr class="abbrev">ETS 300 706</abbr>]</a>, <a class="xref" href="bi01.html#itu653" title="ITU-R Recommendation BT.653-3 "Teletext systems"">[<abbr class="abbrev">ITU BT.653</abbr>]</a></td><td valign="top">PAL/SECAM line 7-22, 320-335 (second field 7-22)</td><td valign="top">Last 42 of the 45 byte Teletext packet, that is
without clock run-in and framing code, lsb first transmitted.</td></tr><tr><td valign="top"><code class="constant">V4L2_SLICED_VPS</code></td><td valign="top">0x0400</td><td valign="top"><a class="xref" href="bi01.html#ets300231" title="ETS 300 231 "Specification of the domestic video Programme Delivery Control system (PDC)"">[<abbr class="abbrev">ETS 300 231</abbr>]</a></td><td valign="top">PAL line 16</td><td valign="top">Byte number 3 to 15 according to Figure 9 of
ETS 300 231, lsb first transmitted.</td></tr><tr><td valign="top"><code class="constant">V4L2_SLICED_CAPTION_525</code></td><td valign="top">0x1000</td><td valign="top"><a class="xref" href="bi01.html#eia608" title="EIA 608-B "Recommended Practice for Line 21 Data Service"">[<abbr class="abbrev">EIA 608-B</abbr>]</a></td><td valign="top">NTSC line 21, 284 (second field 21)</td><td valign="top">Two bytes in transmission order, including parity
bit, lsb first transmitted.</td></tr><tr><td valign="top"><code class="constant">V4L2_SLICED_WSS_625</code></td><td valign="top">0x4000</td><td valign="top"><a class="xref" href="bi01.html#en300294" title="EN 300 294 "625-line television Wide Screen Signalling (WSS)"">[<abbr class="abbrev">EN 300 294</abbr>]</a>, <a class="xref" href="bi01.html#itu1119" title="ITU-R Recommendation BT.1119 "625-line television Wide Screen Signalling (WSS)"">[<abbr class="abbrev">ITU BT.1119</abbr>]</a></td><td valign="top">PAL/SECAM line 23</td><td valign="top"><pre class="screen">
Byte 0 1
msb lsb msb lsb
Bit 7 6 5 4 3 2 1 0 x x 13 12 11 10 9
</pre></td></tr><tr><td valign="top"><code class="constant">V4L2_SLICED_VBI_525</code></td><td valign="top">0x1000</td><td colspan="3" valign="top">Set of services applicable to 525
line systems.</td></tr><tr><td valign="top"><code class="constant">V4L2_SLICED_VBI_625</code></td><td valign="top">0x4401</td><td colspan="3" valign="top">Set of services applicable to 625
line systems.</td></tr></tbody></table></div></div><br class="table-break" /></div><div class="refsect1" title="Return Value"><a id="id2913151"></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 device does not support sliced VBI capturing or
output, or the value in the <em class="structfield"><code>type</code></em> field is
wrong.</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="re48.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="re50.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ioctl VIDIOC_G_PRIORITY, VIDIOC_S_PRIORITY </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_STD, VIDIOC_S_STD</td></tr></table></div></body></html>
