mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 18:24:14 +08:00
c6401af669
This removes comment tags intended for emacs configuration from 67 files in the Media API DocBook. Such comments are not really helpful and violate the coding style rules. Signed-off-by: Sylwester Nawrocki <snjw23@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
384 lines
14 KiB
XML
384 lines
14 KiB
XML
<refentry id="vidioc-enumstd">
|
|
<refmeta>
|
|
<refentrytitle>ioctl VIDIOC_ENUMSTD</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>VIDIOC_ENUMSTD</refname>
|
|
<refpurpose>Enumerate supported video standards</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_standard *<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_ENUMSTD</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>argp</parameter></term>
|
|
<listitem>
|
|
<para></para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>To query the attributes of a video standard,
|
|
especially a custom (driver defined) one, applications initialize the
|
|
<structfield>index</structfield> field of &v4l2-standard; and call the
|
|
<constant>VIDIOC_ENUMSTD</constant> ioctl with a pointer to this
|
|
structure. Drivers fill the rest of the structure or return an
|
|
&EINVAL; when the index is out of bounds. To enumerate all standards
|
|
applications shall begin at index zero, incrementing by one until the
|
|
driver returns <errorcode>EINVAL</errorcode>. Drivers may enumerate a
|
|
different set of standards after switching the video input or
|
|
output.<footnote>
|
|
<para>The supported standards may overlap and we need an
|
|
unambiguous set to find the current standard returned by
|
|
<constant>VIDIOC_G_STD</constant>.</para>
|
|
</footnote></para>
|
|
|
|
<table pgwide="1" frame="none" id="v4l2-standard">
|
|
<title>struct <structname>v4l2_standard</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>index</structfield></entry>
|
|
<entry>Number of the video standard, set by the
|
|
application.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>&v4l2-std-id;</entry>
|
|
<entry><structfield>id</structfield></entry>
|
|
<entry>The bits in this field identify the standard as
|
|
one of the common standards listed in <xref linkend="v4l2-std-id" />,
|
|
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
|
|
<structfield>id</structfield> must be unique. No other enumerated
|
|
<structname>v4l2_standard</structname> structure, for this input or
|
|
output anyway, can contain the same set of bits.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u8</entry>
|
|
<entry><structfield>name</structfield>[24]</entry>
|
|
<entry>Name of the standard, a NUL-terminated ASCII
|
|
string, for example: "PAL-B/G", "NTSC Japan". This information is
|
|
intended for the user.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>&v4l2-fract;</entry>
|
|
<entry><structfield>frameperiod</structfield></entry>
|
|
<entry>The frame period (not field period) is numerator
|
|
/ denominator. For example M/NTSC has a frame period of 1001 /
|
|
30000 seconds.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>framelines</structfield></entry>
|
|
<entry>Total lines per frame including blanking,
|
|
e. g. 625 for B/PAL.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>reserved</structfield>[4]</entry>
|
|
<entry>Reserved for future extensions. Drivers must set
|
|
the array to zero.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<table pgwide="1" frame="none" id="v4l2-fract">
|
|
<title>struct <structname>v4l2_fract</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>numerator</structfield></entry>
|
|
<entry></entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>denominator</structfield></entry>
|
|
<entry></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<table pgwide="1" frame="none" id="v4l2-std-id">
|
|
<title>typedef <structname>v4l2_std_id</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>__u64</entry>
|
|
<entry><structfield>v4l2_std_id</structfield></entry>
|
|
<entry>This type is a set, each bit representing another
|
|
video standard as listed below and in <xref
|
|
linkend="video-standards" />. The 32 most significant bits are reserved
|
|
for custom (driver defined) video standards.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para><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)
|
|
</programlisting></para><para><constant>V4L2_STD_PAL_60</constant> 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.</para><para><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)
|
|
</programlisting></para><para><constant>V4L2_STD_NTSC_443</constant>
|
|
is a hybrid standard with 525 lines, 60 Hz refresh rate, and NTSC
|
|
color modulation with a 4.43 MHz color
|
|
subcarrier.</para><para><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)
|
|
</programlisting></para><para><!-- ATSC proposal by Mark McClelland,
|
|
video4linux-list@redhat.com on 17 Oct 2002
|
|
--><constant>V4L2_STD_ATSC_8_VSB</constant> and
|
|
<constant>V4L2_STD_ATSC_16_VSB</constant> are U.S. terrestrial digital
|
|
TV standards. Presently the V4L2 API does not support digital TV. See
|
|
also the Linux DVB API at <ulink
|
|
url="http://linuxtv.org">http://linuxtv.org</ulink>.</para>
|
|
<para><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)
|
|
</programlisting></para>
|
|
|
|
<table pgwide="1" id="video-standards" orient="land">
|
|
<title>Video Standards (based on [<xref linkend="itu470" />])</title>
|
|
<tgroup cols="12" colsep="1" rowsep="1" align="center">
|
|
<colspec colname="c1" align="left" />
|
|
<colspec colname="c2" />
|
|
<colspec colname="c3" />
|
|
<colspec colname="c4" />
|
|
<colspec colname="c5" />
|
|
<colspec colnum="7" colname="c7" />
|
|
<colspec colnum="9" colname="c9" />
|
|
<colspec colnum="12" colname="c12" />
|
|
<spanspec namest="c2" nameend="c3" spanname="m" align="center" />
|
|
<spanspec namest="c4" nameend="c12" spanname="x" align="center" />
|
|
<spanspec namest="c5" nameend="c7" spanname="b" align="center" />
|
|
<spanspec namest="c9" nameend="c12" spanname="s" align="center" />
|
|
<thead>
|
|
<row>
|
|
<entry>Characteristics</entry>
|
|
<entry><para>M/NTSC<footnote><para>Japan uses a standard
|
|
similar to M/NTSC
|
|
(V4L2_STD_NTSC_M_JP).</para></footnote></para></entry>
|
|
<entry>M/PAL</entry>
|
|
<entry><para>N/PAL<footnote><para> The values in
|
|
brackets apply to the combination N/PAL a.k.a.
|
|
N<subscript>C</subscript> used in Argentina
|
|
(V4L2_STD_PAL_Nc).</para></footnote></para></entry>
|
|
<entry align="center">B, B1, G/PAL</entry>
|
|
<entry align="center">D, D1, K/PAL</entry>
|
|
<entry align="center">H/PAL</entry>
|
|
<entry align="center">I/PAL</entry>
|
|
<entry align="center">B, G/SECAM</entry>
|
|
<entry align="center">D, K/SECAM</entry>
|
|
<entry align="center">K1/SECAM</entry>
|
|
<entry align="center">L/SECAM</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>Frame lines</entry>
|
|
<entry spanname="m">525</entry>
|
|
<entry spanname="x">625</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Frame period (s)</entry>
|
|
<entry spanname="m">1001/30000</entry>
|
|
<entry spanname="x">1/25</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Chrominance sub-carrier frequency (Hz)</entry>
|
|
<entry>3579545 ± 10</entry>
|
|
<entry>3579611.49 ± 10</entry>
|
|
<entry>4433618.75 ± 5 (3582056.25
|
|
± 5)</entry>
|
|
<entry spanname="b">4433618.75 ± 5</entry>
|
|
<entry>4433618.75 ± 1</entry>
|
|
<entry spanname="s">f<subscript>OR</subscript> =
|
|
4406250 ± 2000, f<subscript>OB</subscript> = 4250000
|
|
± 2000</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Nominal radio-frequency channel bandwidth
|
|
(MHz)</entry>
|
|
<entry>6</entry>
|
|
<entry>6</entry>
|
|
<entry>6</entry>
|
|
<entry>B: 7; B1, G: 8</entry>
|
|
<entry>8</entry>
|
|
<entry>8</entry>
|
|
<entry>8</entry>
|
|
<entry>8</entry>
|
|
<entry>8</entry>
|
|
<entry>8</entry>
|
|
<entry>8</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Sound carrier relative to vision carrier
|
|
(MHz)</entry>
|
|
<entry>+ 4.5</entry>
|
|
<entry>+ 4.5</entry>
|
|
<entry>+ 4.5</entry>
|
|
<entry><para>+ 5.5 ± 0.001
|
|
<footnote><para>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.</para></footnote> <footnote><para>New Zealand uses a sound
|
|
carrier displaced 5.4996 ± 0.0005 MHz from the vision
|
|
carrier.</para></footnote> <footnote><para>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)</para></footnote> <footnote><para>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)</para></footnote></para></entry>
|
|
<entry>+ 6.5 ± 0.001</entry>
|
|
<entry>+ 5.5</entry>
|
|
<entry>+ 5.9996 ± 0.0005</entry>
|
|
<entry>+ 5.5 ± 0.001</entry>
|
|
<entry>+ 6.5 ± 0.001</entry>
|
|
<entry>+ 6.5</entry>
|
|
<entry><para>+ 6.5 <footnote><para>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)</para></footnote></para></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
&return-value;
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorcode>EINVAL</errorcode></term>
|
|
<listitem>
|
|
<para>The &v4l2-standard; <structfield>index</structfield>
|
|
is out of bounds.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
</refentry>
|