1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> 2 <HTML 3 ><HEAD 4 ><TITLE 5 >ioctl VIDIOC_G_STD, VIDIOC_S_STD</TITLE 6 ><META 7 NAME="GENERATOR" 8 CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK 9 REL="HOME" 10 TITLE="Video for Linux Two API Specification" 11 HREF="book1.htm"><LINK 12 REL="UP" 13 TITLE="Function Reference" 14 HREF="r7624.htm"><LINK 15 REL="PREVIOUS" 16 TITLE="ioctl VIDIOC_G_SLICED_VBI_CAP" 17 HREF="r12051.htm"><LINK 18 REL="NEXT" 19 TITLE="ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER" 20 HREF="r12342.htm"></HEAD 21 ><BODY 22 CLASS="REFENTRY" 23 BGCOLOR="#FFFFFF" 24 TEXT="#000000" 25 LINK="#0000FF" 26 VLINK="#840084" 27 ALINK="#0000FF" 28 ><DIV 29 CLASS="NAVHEADER" 30 ><TABLE 31 SUMMARY="Header navigation table" 32 WIDTH="100%" 33 BORDER="0" 34 CELLPADDING="0" 35 CELLSPACING="0" 36 ><TR 37 ><TH 38 COLSPAN="3" 39 ALIGN="center" 40 >Video for Linux Two API Specification: Revision 0.24</TH 41 ></TR 42 ><TR 43 ><TD 44 WIDTH="10%" 45 ALIGN="left" 46 VALIGN="bottom" 47 ><A 48 HREF="r12051.htm" 49 ACCESSKEY="P" 50 >Prev</A 51 ></TD 52 ><TD 53 WIDTH="80%" 54 ALIGN="center" 55 VALIGN="bottom" 56 ></TD 57 ><TD 58 WIDTH="10%" 59 ALIGN="right" 60 VALIGN="bottom" 61 ><A 62 HREF="r12342.htm" 63 ACCESSKEY="N" 64 >Next</A 65 ></TD 66 ></TR 67 ></TABLE 68 ><HR 69 ALIGN="LEFT" 70 WIDTH="100%"></DIV 71 ><H1 72 ><A 73 NAME="VIDIOC-G-STD" 74 ></A 75 >ioctl VIDIOC_G_STD, VIDIOC_S_STD</H1 76 ><DIV 77 CLASS="REFNAMEDIV" 78 ><A 79 NAME="AEN12269" 80 ></A 81 ><H2 82 >Name</H2 83 >VIDIOC_G_STD, VIDIOC_S_STD -- Query or select the video standard of the current input</DIV 84 ><DIV 85 CLASS="REFSYNOPSISDIV" 86 ><A 87 NAME="AEN12273" 88 ></A 89 ><H2 90 >Synopsis</H2 91 ><DIV 92 CLASS="FUNCSYNOPSIS" 93 ><P 94 ></P 95 ><A 96 NAME="AEN12274" 97 ></A 98 ><P 99 ><CODE 100 ><CODE 101 CLASS="FUNCDEF" 102 >int ioctl</CODE 103 >(int fd, int request, v4l2_std_id 104 *argp);</CODE 105 ></P 106 ><P 107 ></P 108 ></DIV 109 ><DIV 110 CLASS="FUNCSYNOPSIS" 111 ><P 112 ></P 113 ><A 114 NAME="AEN12284" 115 ></A 116 ><P 117 ><CODE 118 ><CODE 119 CLASS="FUNCDEF" 120 >int ioctl</CODE 121 >(int fd, int request, const v4l2_std_id 122 *argp);</CODE 123 ></P 124 ><P 125 ></P 126 ></DIV 127 ></DIV 128 ><DIV 129 CLASS="REFSECT1" 130 ><A 131 NAME="AEN12294" 132 ></A 133 ><H2 134 >Arguments</H2 135 ><P 136 ></P 137 ><DIV 138 CLASS="VARIABLELIST" 139 ><DL 140 ><DT 141 ><CODE 142 CLASS="PARAMETER" 143 >fd</CODE 144 ></DT 145 ><DD 146 ><P 147 >File descriptor returned by <A 148 HREF="r14090.htm" 149 ><CODE 150 CLASS="FUNCTION" 151 >open()</CODE 152 ></A 153 >.</P 154 ></DD 155 ><DT 156 ><CODE 157 CLASS="PARAMETER" 158 >request</CODE 159 ></DT 160 ><DD 161 ><P 162 >VIDIOC_G_STD, VIDIOC_S_STD</P 163 ></DD 164 ><DT 165 ><CODE 166 CLASS="PARAMETER" 167 >argp</CODE 168 ></DT 169 ><DD 170 ><P 171 ></P 172 ></DD 173 ></DL 174 ></DIV 175 ></DIV 176 ><DIV 177 CLASS="REFSECT1" 178 ><A 179 NAME="AEN12314" 180 ></A 181 ><H2 182 >Description</H2 183 ><P 184 >To query and select the current video standard applications 185 use the <CODE 186 CLASS="CONSTANT" 187 >VIDIOC_G_STD</CODE 188 > and <CODE 189 CLASS="CONSTANT" 190 >VIDIOC_S_STD</CODE 191 > ioctls which take a pointer to a 192 <A 193 HREF="r9288.htm#V4L2-STD-ID" 194 >v4l2_std_id</A 195 > type as argument. <CODE 196 CLASS="CONSTANT" 197 >VIDIOC_G_STD</CODE 198 > can 199 return a single flag or a set of flags as in struct <A 200 HREF="r9288.htm#V4L2-STANDARD" 201 >v4l2_standard</A 202 > field 203 <CODE 204 CLASS="STRUCTFIELD" 205 >id</CODE 206 >. The flags must be unambiguous such 207 that they appear in only one enumerated <CODE 208 CLASS="STRUCTNAME" 209 >v4l2_standard</CODE 210 > structure.</P 211 ><P 212 ><CODE 213 CLASS="CONSTANT" 214 >VIDIOC_S_STD</CODE 215 > accepts one or more 216 flags, being a write-only ioctl it does not return the actual new standard as 217 <CODE 218 CLASS="CONSTANT" 219 >VIDIOC_G_STD</CODE 220 > does. When no flags are given or 221 the current input does not support the requested standard the driver 222 returns an <SPAN 223 CLASS="ERRORCODE" 224 >EINVAL</SPAN 225 > error code. When the standard set is ambiguous drivers may 226 return <SPAN 227 CLASS="ERRORCODE" 228 >EINVAL</SPAN 229 > or choose any of the requested 230 standards.</P 231 ></DIV 232 ><DIV 233 CLASS="REFSECT1" 234 ><A 235 NAME="AEN12329" 236 ></A 237 ><H2 238 >Return Value</H2 239 ><P 240 >On success <SPAN 241 CLASS="RETURNVALUE" 242 >0</SPAN 243 > is returned, on error <SPAN 244 CLASS="RETURNVALUE" 245 >-1</SPAN 246 > and the <CODE 247 CLASS="VARNAME" 248 >errno</CODE 249 > variable is set appropriately:</P 250 ><P 251 ></P 252 ><DIV 253 CLASS="VARIABLELIST" 254 ><DL 255 ><DT 256 ><SPAN 257 CLASS="ERRORCODE" 258 >EINVAL</SPAN 259 ></DT 260 ><DD 261 ><P 262 >This ioctl is not supported, or the 263 <CODE 264 CLASS="CONSTANT" 265 >VIDIOC_S_STD</CODE 266 > parameter was unsuitable.</P 267 ></DD 268 ></DL 269 ></DIV 270 ></DIV 271 ><DIV 272 CLASS="NAVFOOTER" 273 ><HR 274 ALIGN="LEFT" 275 WIDTH="100%"><TABLE 276 SUMMARY="Footer navigation table" 277 WIDTH="100%" 278 BORDER="0" 279 CELLPADDING="0" 280 CELLSPACING="0" 281 ><TR 282 ><TD 283 WIDTH="33%" 284 ALIGN="left" 285 VALIGN="top" 286 ><A 287 HREF="r12051.htm" 288 ACCESSKEY="P" 289 >Prev</A 290 ></TD 291 ><TD 292 WIDTH="34%" 293 ALIGN="center" 294 VALIGN="top" 295 ><A 296 HREF="book1.htm" 297 ACCESSKEY="H" 298 >Home</A 299 ></TD 300 ><TD 301 WIDTH="33%" 302 ALIGN="right" 303 VALIGN="top" 304 ><A 305 HREF="r12342.htm" 306 ACCESSKEY="N" 307 >Next</A 308 ></TD 309 ></TR 310 ><TR 311 ><TD 312 WIDTH="33%" 313 ALIGN="left" 314 VALIGN="top" 315 >ioctl VIDIOC_G_SLICED_VBI_CAP</TD 316 ><TD 317 WIDTH="34%" 318 ALIGN="center" 319 VALIGN="top" 320 ><A 321 HREF="r7624.htm" 322 ACCESSKEY="U" 323 >Up</A 324 ></TD 325 ><TD 326 WIDTH="33%" 327 ALIGN="right" 328 VALIGN="top" 329 >ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</TD 330 ></TR 331 ></TABLE 332 ></DIV 333 ></BODY 334 ></HTML 335 > 336
