Based on kernel version 4.7.2. Page generated on 2016-08-22 22:45 EST.
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 52 initialize the <structfield>index</structfield> field of &v4l2-output; 53 and call the <constant>VIDIOC_ENUMOUTPUT</constant> ioctl with a 54 pointer to this structure. Drivers fill the rest of the structure or 55 return an &EINVAL; when the index is out of bounds. To enumerate all 56 outputs applications shall begin at index zero, incrementing by one 57 until 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 68 application.</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 74 string, for example: "Vout". This information is intended for the 75 user, 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 87 audio outputs. This field shows which audio outputs were 88 selectable as the current output if this was the currently selected 89 video output. It is a bit mask. The LSB corresponds to audio output 0, 90 the MSB to output 31. Any number of bits can be set, or 91 none.</para><para>When the driver does not enumerate audio outputs no 92 bits must be set. Applications shall not interpret this as lack of 93 audio support. Drivers may automatically select audio outputs without 94 enumerating them.</para><para>For details on audio outputs and how to 95 select 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. 101 When the <structfield>type</structfield> is 102 <constant>V4L2_OUTPUT_TYPE_MODULATOR</constant> this is an RF 103 connector and this field identifies the modulator. It corresponds to 104 &v4l2-modulator; field <structfield>index</structfield>. For details 105 on 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 111 video standards. This field is a set of all supported standards. For 112 details 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 119 output. 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 125 the 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 / 145 CVBS, 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 157 Karicheri, titled RFC (v1.2): V4L - Support for video timings at the 158 input/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_DV_TIMINGS</constant></entry> 167 <entry>0x00000002</entry> 168 <entry>This output supports setting video timings by using VIDIOC_S_DV_TIMINGS.</entry> 169 </row> 170 <row> 171 <entry><constant>V4L2_OUT_CAP_STD</constant></entry> 172 <entry>0x00000004</entry> 173 <entry>This output supports setting the TV standard by using VIDIOC_S_STD.</entry> 174 </row> 175 <row> 176 <entry><constant>V4L2_OUT_CAP_NATIVE_SIZE</constant></entry> 177 <entry>0x00000008</entry> 178 <entry>This output supports setting the native size using 179 the <constant>V4L2_SEL_TGT_NATIVE_SIZE</constant> 180 selection target, see <xref 181 linkend="v4l2-selections-common"/>.</entry> 182 </row> 183 </tbody> 184 </tgroup> 185 </table> 186 187 </refsect1> 188 <refsect1> 189 &return-value; 190 191 <variablelist> 192 <varlistentry> 193 <term><errorcode>EINVAL</errorcode></term> 194 <listitem> 195 <para>The &v4l2-output; <structfield>index</structfield> 196 is out of bounds.</para> 197 </listitem> 198 </varlistentry> 199 </variablelist> 200 </refsect1> 201 </refentry>
