| <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> |
| <varlistentry> |
| <term><errorcode>ENODATA</errorcode></term> |
| <listitem> |
| <para>Standard video timings are not supported for this input or output.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| </refentry> |
