doc/spec/r12051.htm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>ioctl VIDIOC_G_SLICED_VBI_CAP</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="Video for Linux Two API Specification"
HREF="book1.htm"><LINK
REL="UP"
TITLE="Function Reference"
HREF="r7624.htm"><LINK
REL="PREVIOUS"
TITLE="ioctl VIDIOC_G_PRIORITY, VIDIOC_S_PRIORITY"
HREF="r11946.htm"><LINK
REL="NEXT"
TITLE="ioctl VIDIOC_G_STD, VIDIOC_S_STD"
HREF="r12265.htm"></HEAD
><BODY
CLASS="REFENTRY"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>Video for Linux Two API Specification: Revision 0.24</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="r11946.htm"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="r12265.htm"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="VIDIOC-G-SLICED-VBI-CAP"
></A
>ioctl VIDIOC_G_SLICED_VBI_CAP</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN12055"
></A
><H2
>Name</H2
>VIDIOC_G_SLICED_VBI_CAP&nbsp;--&nbsp;Query sliced VBI capabilities</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN12058"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><P
></P
><A
NAME="AEN12059"
></A
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int ioctl</CODE
>(int fd, int request, struct v4l2_sliced_vbi_cap *argp);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN12069"
></A
><H2
>Arguments</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><CODE
CLASS="PARAMETER"
>fd</CODE
></DT
><DD
><P
>File descriptor returned by <A
HREF="r14090.htm"
><CODE
CLASS="FUNCTION"
>open()</CODE
></A
>.</P
></DD
><DT
><CODE
CLASS="PARAMETER"
>request</CODE
></DT
><DD
><P
>VIDIOC_G_SLICED_VBI_CAP</P
></DD
><DT
><CODE
CLASS="PARAMETER"
>argp</CODE
></DT
><DD
><P
></P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN12089"
></A
><H2
>Description</H2
><P
>To find out which data services are supported by a sliced
VBI capture or output device, applications initialize the
<CODE
CLASS="STRUCTFIELD"
>type</CODE
> field of a struct&nbsp;<A
HREF="r12051.htm#V4L2-SLICED-VBI-CAP"
>v4l2_sliced_vbi_cap</A
>,
clear the <CODE
CLASS="STRUCTFIELD"
>reserved</CODE
> 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 <CODE
CLASS="STRUCTFIELD"
>type</CODE
>
is invalid.</P
><P
>Note the <CODE
CLASS="STRUCTFIELD"
>type</CODE
> field was added,
and the ioctl changed from read-only to write-read, in Linux 2.6.19.</P
><DIV
CLASS="TABLE"
><A
NAME="V4L2-SLICED-VBI-CAP"
></A
><P
><B
>Table 1. struct <CODE
CLASS="STRUCTNAME"
>v4l2_sliced_vbi_cap</CODE
></B
></P
><TABLE
BORDER="0"
FRAME="void"
WIDTH="100%"
CLASS="CALSTABLE"
><COL
WIDTH="25%"
TITLE="C1"><COL
WIDTH="25%"
TITLE="C2"><COL
WIDTH="17%"
TITLE="C3"><COL
WIDTH="17%"
TITLE="C4"><COL
WIDTH="17%"
TITLE="C5"><TBODY
VALIGN="TOP"
><TR
><TD
>__u16</TD
><TD
><CODE
CLASS="STRUCTFIELD"
>service_set</CODE
></TD
><TD
COLSPAN="3"
>A set of all data services
supported by the driver. Equal to the union of all elements of the
<CODE
CLASS="STRUCTFIELD"
>service_lines </CODE
> array.</TD
></TR
><TR
><TD
>__u16</TD
><TD
><CODE
CLASS="STRUCTFIELD"
>service_lines</CODE
>[2][24]</TD
><TD
COLSPAN="3"
>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
HREF="r12051.htm#VBI-SERVICES"
>Table 2</A
>. Array indices map to ITU-R
line numbers (see also <A
HREF="x7013.htm#VBI-525"
>Figure 4-2</A
> and <A
HREF="x7013.htm#VBI-625"
>Figure 4-3</A
>) as follows:</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
>Element</TD
><TD
>525 line systems</TD
><TD
>625 line systems</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
><CODE
CLASS="STRUCTFIELD"
>service_lines</CODE
>[0][1]</TD
><TD
ALIGN="CENTER"
>1</TD
><TD
ALIGN="CENTER"
>1</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
><CODE
CLASS="STRUCTFIELD"
>service_lines</CODE
>[0][23]</TD
><TD
ALIGN="CENTER"
>23</TD
><TD
ALIGN="CENTER"
>23</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
><CODE
CLASS="STRUCTFIELD"
>service_lines</CODE
>[1][1]</TD
><TD
ALIGN="CENTER"
>264</TD
><TD
ALIGN="CENTER"
>314</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
><CODE
CLASS="STRUCTFIELD"
>service_lines</CODE
>[1][23]</TD
><TD
ALIGN="CENTER"
>286</TD
><TD
ALIGN="CENTER"
>336</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
COLSPAN="3"
>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
HREF="r10944.htm"
><CODE
CLASS="CONSTANT"
>VIDIOC_S_FMT</CODE
></A
> ioctl as described in <A
HREF="x7236.htm"
>Section 4.8</A
>.</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
></TR
><TR
><TD
>&nbsp;</TD
><TD
>&nbsp;</TD
><TD
COLSPAN="3"
>Drivers must set
<CODE
CLASS="STRUCTFIELD"
>service_lines</CODE
>[0][0] and
<CODE
CLASS="STRUCTFIELD"
>service_lines</CODE
>[1][0] to zero.</TD
></TR
><TR
><TD
>enum&nbsp;<A
HREF="x5953.htm#V4L2-BUF-TYPE"
>v4l2_buf_type</A
></TD
><TD
><CODE
CLASS="STRUCTFIELD"
>type</CODE
></TD
><TD
>Type of the data stream, see <A
HREF="x5953.htm#V4L2-BUF-TYPE"
>Table 3-2</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
>&nbsp;</TD
><TD
>&nbsp;</TD
></TR
><TR
><TD
>__u32</TD
><TD
><CODE
CLASS="STRUCTFIELD"
>reserved</CODE
>[3]</TD
><TD
COLSPAN="3"
>This array is reserved for future
extensions. Applications and drivers must set it to zero.</TD
></TR
></TBODY
></TABLE
></DIV
><DIV
CLASS="TABLE"
><A
NAME="VBI-SERVICES"
></A
><P
><B
>Table 2. Sliced VBI services</B
></P
><TABLE
BORDER="0"
FRAME="void"
WIDTH="100%"
CLASS="CALSTABLE"
><COL
WIDTH="25%"
TITLE="C1"><COL
WIDTH="12%"
TITLE="C2"><COL
WIDTH="12%"
TITLE="C3"><COL
WIDTH="25%"
TITLE="C4"><COL
WIDTH="25%"
TITLE="C5"><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
><CODE
CLASS="CONSTANT"
>V4L2_SLICED_TELETEXT_B</CODE
> (Teletext
System B)</TD
><TD
>0x0001</TD
><TD
><A
HREF="b17127.htm#ETS300706"
><ABBR
CLASS="ABBREV"
>ETS&nbsp;300&nbsp;706</ABBR
></A
>, <A
HREF="b17127.htm#ITU653"
><ABBR
CLASS="ABBREV"
>ITU&nbsp;BT.653</ABBR
></A
></TD
><TD
>PAL/SECAM line 7-22, 320-335 (second field 7-22)</TD
><TD
>Last 42 of the 45 byte Teletext packet, that is
without clock run-in and framing code, lsb first transmitted.</TD
></TR
><TR
><TD
><CODE
CLASS="CONSTANT"
>V4L2_SLICED_VPS</CODE
></TD
><TD
>0x0400</TD
><TD
><A
HREF="b17127.htm#ETS300231"
><ABBR
CLASS="ABBREV"
>ETS&nbsp;300&nbsp;231</ABBR
></A
></TD
><TD
>PAL line 16</TD
><TD
>Byte number 3 to 15 according to Figure 9 of
ETS&nbsp;300&nbsp;231, lsb first transmitted.</TD
></TR
><TR
><TD
><CODE
CLASS="CONSTANT"
>V4L2_SLICED_CAPTION_525</CODE
></TD
><TD
>0x1000</TD
><TD
><A
HREF="b17127.htm#EIA608"
><ABBR
CLASS="ABBREV"
>EIA&nbsp;608-B</ABBR
></A
></TD
><TD
>NTSC line 21, 284 (second field 21)</TD
><TD
>Two bytes in transmission order, including parity
bit, lsb first transmitted.</TD
></TR
><TR
><TD
><CODE
CLASS="CONSTANT"
>V4L2_SLICED_WSS_625</CODE
></TD
><TD
>0x4000</TD
><TD
><A
HREF="b17127.htm#EN300294"
><ABBR
CLASS="ABBREV"
>EN&nbsp;300&nbsp;294</ABBR
></A
>, <A
HREF="b17127.htm#ITU1119"
><ABBR
CLASS="ABBREV"
>ITU&nbsp;BT.1119</ABBR
></A
></TD
><TD
>PAL/SECAM line 23</TD
><TD
><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
><CODE
CLASS="CONSTANT"
>V4L2_SLICED_VBI_525</CODE
></TD
><TD
>0x1000</TD
><TD
COLSPAN="3"
>Set of services applicable to 525
line systems.</TD
></TR
><TR
><TD
><CODE
CLASS="CONSTANT"
>V4L2_SLICED_VBI_625</CODE
></TD
><TD
>0x4401</TD
><TD
COLSPAN="3"
>Set of services applicable to 625
line systems.</TD
></TR
></TBODY
></TABLE
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN12252"
></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
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><SPAN
CLASS="ERRORCODE"
>EINVAL</SPAN
></DT
><DD
><P
>The device does not support sliced VBI capturing or
output, or the value in the <CODE
CLASS="STRUCTFIELD"
>type</CODE
> field is
wrong.</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="r11946.htm"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="book1.htm"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="r12265.htm"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>ioctl VIDIOC_G_PRIORITY, VIDIOC_S_PRIORITY</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="r7624.htm"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>ioctl VIDIOC_G_STD, VIDIOC_S_STD</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>