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Diffstat (limited to 'Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml')
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diff --git a/Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml b/Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml new file mode 100644 index 00000000000..10e721b1737 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml @@ -0,0 +1,264 @@ +<refentry id="vidioc-g-sliced-vbi-cap"> + <refmeta> + <refentrytitle>ioctl VIDIOC_G_SLICED_VBI_CAP</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_G_SLICED_VBI_CAP</refname> + <refpurpose>Query sliced VBI capabilities</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcprototype> + <funcdef>int <function>ioctl</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>int <parameter>request</parameter></paramdef> + <paramdef>struct v4l2_sliced_vbi_cap *<parameter>argp</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Arguments</title> + + <variablelist> + <varlistentry> + <term><parameter>fd</parameter></term> + <listitem> + <para>&fd;</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>request</parameter></term> + <listitem> + <para>VIDIOC_G_SLICED_VBI_CAP</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <para>To find out which data services are supported by a sliced +VBI capture or output device, applications initialize the +<structfield>type</structfield> field of a &v4l2-sliced-vbi-cap;, +clear the <structfield>reserved</structfield> array and +call the <constant>VIDIOC_G_SLICED_VBI_CAP</constant> ioctl. The +driver fills in the remaining fields or returns an &EINVAL; if the +sliced VBI API is unsupported or <structfield>type</structfield> +is invalid.</para> + + <para>Note the <structfield>type</structfield> field was added, +and the ioctl changed from read-only to write-read, in Linux 2.6.19.</para> + + <table pgwide="1" frame="none" id="v4l2-sliced-vbi-cap"> + <title>struct <structname>v4l2_sliced_vbi_cap</structname></title> + <tgroup cols="5"> + <colspec colname="c1" colwidth="3*" /> + <colspec colname="c2" colwidth="3*" /> + <colspec colname="c3" colwidth="2*" /> + <colspec colname="c4" colwidth="2*" /> + <colspec colname="c5" colwidth="2*" /> + <spanspec spanname="hspan" namest="c3" nameend="c5" /> + <tbody valign="top"> + <row> + <entry>__u16</entry> + <entry><structfield>service_set</structfield></entry> + <entry spanname="hspan">A set of all data services +supported by the driver. Equal to the union of all elements of the +<structfield>service_lines </structfield> array.</entry> + </row> + <row> + <entry>__u16</entry> + <entry><structfield>service_lines</structfield>[2][24]</entry> + <entry spanname="hspan">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 <xref + linkend="vbi-services" />. Array indices map to ITU-R +line numbers (see also <xref + linkend="vbi-525" /> and <xref +linkend="vbi-625" />) as follows:</entry> + </row> + <row> + <entry></entry> + <entry></entry> + <entry>Element</entry> + <entry>525 line systems</entry> + <entry>625 line systems</entry> + </row> + <row> + <entry></entry> + <entry></entry> + <entry><structfield>service_lines</structfield>[0][1]</entry> + <entry align="center">1</entry> + <entry align="center">1</entry> + </row> + <row> + <entry></entry> + <entry></entry> + <entry><structfield>service_lines</structfield>[0][23]</entry> + <entry align="center">23</entry> + <entry align="center">23</entry> + </row> + <row> + <entry></entry> + <entry></entry> + <entry><structfield>service_lines</structfield>[1][1]</entry> + <entry align="center">264</entry> + <entry align="center">314</entry> + </row> + <row> + <entry></entry> + <entry></entry> + <entry><structfield>service_lines</structfield>[1][23]</entry> + <entry align="center">286</entry> + <entry align="center">336</entry> + </row> + <row> + <entry></entry> + </row> + <row> + <entry></entry> + <entry></entry> + <entry spanname="hspan">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 &VIDIOC-S-FMT; ioctl as described in <xref + linkend="sliced" />.</entry> + </row> + <row> + <entry></entry> + </row> + <row> + <entry></entry> + <entry></entry> + <entry spanname="hspan">Drivers must set +<structfield>service_lines</structfield>[0][0] and +<structfield>service_lines</structfield>[1][0] to zero.</entry> + </row> + <row> + <entry>&v4l2-buf-type;</entry> + <entry><structfield>type</structfield></entry> + <entry>Type of the data stream, see <xref + linkend="v4l2-buf-type" />. Should be +<constant>V4L2_BUF_TYPE_SLICED_VBI_CAPTURE</constant> or +<constant>V4L2_BUF_TYPE_SLICED_VBI_OUTPUT</constant>.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[3]</entry> + <entry spanname="hspan">This array is reserved for future +extensions. Applications and drivers must set it to zero.</entry> + </row> + </tbody> + </tgroup> + </table> + + <!-- See also dev-sliced-vbi.sgml --> + <table pgwide="1" frame="none" id="vbi-services"> + <title>Sliced VBI services</title> + <tgroup cols="5"> + <colspec colname="c1" colwidth="2*" /> + <colspec colname="c2" colwidth="1*" /> + <colspec colname="c3" colwidth="1*" /> + <colspec colname="c4" colwidth="2*" /> + <colspec colname="c5" colwidth="2*" /> + <spanspec spanname='rlp' namest='c3' nameend='c5' /> + <thead> + <row> + <entry>Symbol</entry> + <entry>Value</entry> + <entry>Reference</entry> + <entry>Lines, usually</entry> + <entry>Payload</entry> + </row> + </thead> + <tbody valign="top"> + <row> + <entry><constant>V4L2_SLICED_TELETEXT_B</constant> (Teletext +System B)</entry> + <entry>0x0001</entry> + <entry><xref linkend="ets300706" />, <xref linkend="itu653" /></entry> + <entry>PAL/SECAM line 7-22, 320-335 (second field 7-22)</entry> + <entry>Last 42 of the 45 byte Teletext packet, that is +without clock run-in and framing code, lsb first transmitted.</entry> + </row> + <row> + <entry><constant>V4L2_SLICED_VPS</constant></entry> + <entry>0x0400</entry> + <entry><xref linkend="ets300231" /></entry> + <entry>PAL line 16</entry> + <entry>Byte number 3 to 15 according to Figure 9 of +ETS 300 231, lsb first transmitted.</entry> + </row> + <row> + <entry><constant>V4L2_SLICED_CAPTION_525</constant></entry> + <entry>0x1000</entry> + <entry><xref linkend="eia608" /></entry> + <entry>NTSC line 21, 284 (second field 21)</entry> + <entry>Two bytes in transmission order, including parity +bit, lsb first transmitted.</entry> + </row> + <row> + <entry><constant>V4L2_SLICED_WSS_625</constant></entry> + <entry>0x4000</entry> + <entry><xref linkend="en300294" />, <xref linkend="itu1119" /></entry> + <entry>PAL/SECAM line 23</entry> + <entry><screen> +Byte 0 1 + msb lsb msb lsb +Bit 7 6 5 4 3 2 1 0 x x 13 12 11 10 9 +</screen></entry> + </row> + <row> + <entry><constant>V4L2_SLICED_VBI_525</constant></entry> + <entry>0x1000</entry> + <entry spanname="rlp">Set of services applicable to 525 +line systems.</entry> + </row> + <row> + <entry><constant>V4L2_SLICED_VBI_625</constant></entry> + <entry>0x4401</entry> + <entry spanname="rlp">Set of services applicable to 625 +line systems.</entry> + </row> + </tbody> + </tgroup> + </table> + + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>The device does not support sliced VBI capturing or +output, or the value in the <structfield>type</structfield> field is +wrong.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> + +<!-- +Local Variables: +mode: sgml +sgml-parent-document: "v4l2.sgml" +indent-tabs-mode: nil +End: +--> |