1<refentry id="vidioc-enumoutput"> 2 <refmeta> 3 <refentrytitle>ioctl VIDIOC_ENUMOUTPUT</refentrytitle> 4 &manvol; 5 </refmeta> 6 7 <refnamediv> 8 <refname>VIDIOC_ENUMOUTPUT</refname> 9 <refpurpose>Enumerate video outputs</refpurpose> 10 </refnamediv> 11 12 <refsynopsisdiv> 13 <funcsynopsis> 14 <funcprototype> 15 <funcdef>int <function>ioctl</function></funcdef> 16 <paramdef>int <parameter>fd</parameter></paramdef> 17 <paramdef>int <parameter>request</parameter></paramdef> 18 <paramdef>struct v4l2_output *<parameter>argp</parameter></paramdef> 19 </funcprototype> 20 </funcsynopsis> 21 </refsynopsisdiv> 22 23 <refsect1> 24 <title>Arguments</title> 25 26 <variablelist> 27 <varlistentry> 28 <term><parameter>fd</parameter></term> 29 <listitem> 30 <para>&fd;</para> 31 </listitem> 32 </varlistentry> 33 <varlistentry> 34 <term><parameter>request</parameter></term> 35 <listitem> 36 <para>VIDIOC_ENUMOUTPUT</para> 37 </listitem> 38 </varlistentry> 39 <varlistentry> 40 <term><parameter>argp</parameter></term> 41 <listitem> 42 <para></para> 43 </listitem> 44 </varlistentry> 45 </variablelist> 46 </refsect1> 47 48 <refsect1> 49 <title>Description</title> 50 51 <para>To query the attributes of a video outputs applications 52initialize the <structfield>index</structfield> field of &v4l2-output; 53and call the <constant>VIDIOC_ENUMOUTPUT</constant> ioctl with a 54pointer to this structure. Drivers fill the rest of the structure or 55return an &EINVAL; when the index is out of bounds. To enumerate all 56outputs applications shall begin at index zero, incrementing by one 57until the driver returns <errorcode>EINVAL</errorcode>.</para> 58 59 <table frame="none" pgwide="1" id="v4l2-output"> 60 <title>struct <structname>v4l2_output</structname></title> 61 <tgroup cols="3"> 62 &cs-str; 63 <tbody valign="top"> 64 <row> 65 <entry>__u32</entry> 66 <entry><structfield>index</structfield></entry> 67 <entry>Identifies the output, set by the 68application.</entry> 69 </row> 70 <row> 71 <entry>__u8</entry> 72 <entry><structfield>name</structfield>[32]</entry> 73 <entry>Name of the video output, a NUL-terminated ASCII 74string, for example: "Vout". This information is intended for the 75user, preferably the connector label on the device itself.</entry> 76 </row> 77 <row> 78 <entry>__u32</entry> 79 <entry><structfield>type</structfield></entry> 80 <entry>Type of the output, see <xref 81 linkend="output-type" />.</entry> 82 </row> 83 <row> 84 <entry>__u32</entry> 85 <entry><structfield>audioset</structfield></entry> 86 <entry><para>Drivers can enumerate up to 32 video and 87audio outputs. This field shows which audio outputs were 88selectable as the current output if this was the currently selected 89video output. It is a bit mask. The LSB corresponds to audio output 0, 90the MSB to output 31. Any number of bits can be set, or 91none.</para><para>When the driver does not enumerate audio outputs no 92bits must be set. Applications shall not interpret this as lack of 93audio support. Drivers may automatically select audio outputs without 94enumerating them.</para><para>For details on audio outputs and how to 95select the current output see <xref linkend="audio" />.</para></entry> 96 </row> 97 <row> 98 <entry>__u32</entry> 99 <entry><structfield>modulator</structfield></entry> 100 <entry>Output devices can have zero or more RF modulators. 101When the <structfield>type</structfield> is 102<constant>V4L2_OUTPUT_TYPE_MODULATOR</constant> this is an RF 103connector and this field identifies the modulator. It corresponds to 104&v4l2-modulator; field <structfield>index</structfield>. For details 105on modulators see <xref linkend="tuner" />.</entry> 106 </row> 107 <row> 108 <entry>&v4l2-std-id;</entry> 109 <entry><structfield>std</structfield></entry> 110 <entry>Every video output supports one or more different 111video standards. This field is a set of all supported standards. For 112details on video standards and how to switch see <xref 113 linkend="standard" />.</entry> 114 </row> 115 <row> 116 <entry>__u32</entry> 117 <entry><structfield>capabilities</structfield></entry> 118 <entry>This field provides capabilities for the 119output. See <xref linkend="output-capabilities" /> for flags.</entry> 120 </row> 121 <row> 122 <entry>__u32</entry> 123 <entry><structfield>reserved</structfield>[3]</entry> 124 <entry>Reserved for future extensions. Drivers must set 125the array to zero.</entry> 126 </row> 127 </tbody> 128 </tgroup> 129 </table> 130 131 <table frame="none" pgwide="1" id="output-type"> 132 <title>Output Type</title> 133 <tgroup cols="3"> 134 &cs-def; 135 <tbody valign="top"> 136 <row> 137 <entry><constant>V4L2_OUTPUT_TYPE_MODULATOR</constant></entry> 138 <entry>1</entry> 139 <entry>This output is an analog TV modulator.</entry> 140 </row> 141 <row> 142 <entry><constant>V4L2_OUTPUT_TYPE_ANALOG</constant></entry> 143 <entry>2</entry> 144 <entry>Analog baseband output, for example Composite / 145CVBS, S-Video, RGB.</entry> 146 </row> 147 <row> 148 <entry><constant>V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY</constant></entry> 149 <entry>3</entry> 150 <entry>[?]</entry> 151 </row> 152 </tbody> 153 </tgroup> 154 </table> 155 156 <!-- Capabilities flags based on video timings RFC by Muralidharan 157Karicheri, titled RFC (v1.2): V4L - Support for video timings at the 158input/output interface to linux-media@vger.kernel.org on 19 Oct 2009. 159 --> 160 <table frame="none" pgwide="1" id="output-capabilities"> 161 <title>Output capabilities</title> 162 <tgroup cols="3"> 163 &cs-def; 164 <tbody valign="top"> 165 <row> 166 <entry><constant>V4L2_OUT_CAP_PRESETS</constant></entry> 167 <entry>0x00000001</entry> 168 <entry>This output supports setting DV presets by using VIDIOC_S_DV_PRESET.</entry> 169 </row> 170 <row> 171 <entry><constant>V4L2_OUT_CAP_CUSTOM_TIMINGS</constant></entry> 172 <entry>0x00000002</entry> 173 <entry>This output supports setting custom video timings by using VIDIOC_S_DV_TIMINGS.</entry> 174 </row> 175 <row> 176 <entry><constant>V4L2_OUT_CAP_STD</constant></entry> 177 <entry>0x00000004</entry> 178 <entry>This output supports setting the TV standard by using VIDIOC_S_STD.</entry> 179 </row> 180 </tbody> 181 </tgroup> 182 </table> 183 184 </refsect1> 185 <refsect1> 186 &return-value; 187 188 <variablelist> 189 <varlistentry> 190 <term><errorcode>EINVAL</errorcode></term> 191 <listitem> 192 <para>The &v4l2-output; <structfield>index</structfield> 193is out of bounds.</para> 194 </listitem> 195 </varlistentry> 196 </variablelist> 197 </refsect1> 198</refentry> 199 200<!-- 201Local Variables: 202mode: sgml 203sgml-parent-document: "v4l2.sgml" 204indent-tabs-mode: nil 205End: 206--> 207