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>Function Reference</TITLE 6><META 7NAME="GENERATOR" 8CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK 9REL="HOME" 10TITLE="Video for Linux Two API Specification" 11HREF="book1.htm"><LINK 12REL="PREVIOUS" 13TITLE="RDS Interface" 14HREF="x7607.htm"><LINK 15REL="NEXT" 16TITLE="V4L2 close()" 17HREF="r7626.htm"></HEAD 18><BODY 19CLASS="REFERENCE" 20BGCOLOR="#FFFFFF" 21TEXT="#000000" 22LINK="#0000FF" 23VLINK="#840084" 24ALINK="#0000FF" 25><DIV 26CLASS="NAVHEADER" 27><TABLE 28SUMMARY="Header navigation table" 29WIDTH="100%" 30BORDER="0" 31CELLPADDING="0" 32CELLSPACING="0" 33><TR 34><TH 35COLSPAN="3" 36ALIGN="center" 37>Video for Linux Two API Specification: Revision 0.24</TH 38></TR 39><TR 40><TD 41WIDTH="10%" 42ALIGN="left" 43VALIGN="bottom" 44><A 45HREF="x7607.htm" 46ACCESSKEY="P" 47>Prev</A 48></TD 49><TD 50WIDTH="80%" 51ALIGN="center" 52VALIGN="bottom" 53></TD 54><TD 55WIDTH="10%" 56ALIGN="right" 57VALIGN="bottom" 58><A 59HREF="r7626.htm" 60ACCESSKEY="N" 61>Next</A 62></TD 63></TR 64></TABLE 65><HR 66ALIGN="LEFT" 67WIDTH="100%"></DIV 68><DIV 69CLASS="REFERENCE" 70><A 71NAME="USER-FUNC" 72></A 73><DIV 74CLASS="TITLEPAGE" 75><H1 76CLASS="TITLE" 77>I. Function Reference</H1 78><DIV 79CLASS="TOC" 80><DL 81><DT 82><B 83>Table of Contents</B 84></DT 85><DT 86><A 87HREF="r7626.htm" 88>V4L2 close()</A 89> -- Close a V4L2 device</DT 90><DT 91><A 92HREF="r7667.htm" 93>V4L2 ioctl()</A 94> -- Program a V4L2 device</DT 95><DT 96><A 97HREF="r7771.htm" 98>ioctl VIDIOC_CROPCAP</A 99> -- Information about the video cropping and scaling abilities</DT 100><DT 101><A 102HREF="r7900.htm" 103>ioctl VIDIOC_DBG_G_REGISTER, VIDIOC_DBG_S_REGISTER</A 104> -- Read or write hardware registers</DT 105><DT 106><A 107HREF="r8087.htm" 108>ioctl VIDIOC_ENCODER_CMD, VIDIOC_TRY_ENCODER_CMD</A 109> -- Execute an encoder command</DT 110><DT 111><A 112HREF="r8242.htm" 113>ioctl VIDIOC_ENUMAUDIO</A 114> -- Enumerate audio inputs</DT 115><DT 116><A 117HREF="r8304.htm" 118>ioctl VIDIOC_ENUMAUDOUT</A 119> -- Enumerate audio outputs</DT 120><DT 121><A 122HREF="r8367.htm" 123>ioctl VIDIOC_ENUM_FMT</A 124> -- Enumerate image formats</DT 125><DT 126><A 127HREF="r8494.htm" 128>ioctl VIDIOC_ENUM_FRAMESIZES</A 129> -- Enumerate frame sizes</DT 130><DT 131><A 132HREF="r8724.htm" 133>ioctl VIDIOC_ENUM_FRAMEINTERVALS</A 134> -- Enumerate frame intervals</DT 135><DT 136><A 137HREF="r8936.htm" 138>ioctl VIDIOC_ENUMINPUT</A 139> -- Enumerate video inputs</DT 140><DT 141><A 142HREF="r9149.htm" 143>ioctl VIDIOC_ENUMOUTPUT</A 144> -- Enumerate video outputs</DT 145><DT 146><A 147HREF="r9288.htm" 148>ioctl VIDIOC_ENUMSTD</A 149> -- Enumerate supported video standards</DT 150><DT 151><A 152HREF="r9539.htm" 153>ioctl VIDIOC_G_AUDIO, VIDIOC_S_AUDIO</A 154> -- Query or select the current audio input and its 155attributes</DT 156><DT 157><A 158HREF="r9688.htm" 159>ioctl VIDIOC_G_AUDOUT, VIDIOC_S_AUDOUT</A 160> -- Query or select the current audio output</DT 161><DT 162><A 163HREF="r9804.htm" 164>ioctl VIDIOC_G_CHIP_IDENT</A 165> -- Identify the chips on a TV card</DT 166><DT 167><A 168HREF="r9994.htm" 169>ioctl VIDIOC_G_CROP, VIDIOC_S_CROP</A 170> -- Get or set the current cropping rectangle</DT 171><DT 172><A 173HREF="r10104.htm" 174>ioctl VIDIOC_G_CTRL, VIDIOC_S_CTRL</A 175> -- Get or set the value of a control</DT 176><DT 177><A 178HREF="r10211.htm" 179>ioctl VIDIOC_G_ENC_INDEX</A 180> -- Get meta data about a compressed video stream</DT 181><DT 182><A 183HREF="r10386.htm" 184>ioctl VIDIOC_G_EXT_CTRLS, VIDIOC_S_EXT_CTRLS, 185VIDIOC_TRY_EXT_CTRLS</A 186> -- Get or set the value of several controls, try control 187values</DT 188><DT 189><A 190HREF="r10595.htm" 191>ioctl VIDIOC_G_FBUF, VIDIOC_S_FBUF</A 192> -- Get or set frame buffer overlay parameters</DT 193><DT 194><A 195HREF="r10944.htm" 196>ioctl VIDIOC_G_FMT, VIDIOC_S_FMT, 197VIDIOC_TRY_FMT</A 198> -- Get or set the data format, try a format</DT 199><DT 200><A 201HREF="r11094.htm" 202>ioctl VIDIOC_G_FREQUENCY, VIDIOC_S_FREQUENCY</A 203> -- Get or set tuner or modulator radio 204frequency</DT 205><DT 206><A 207HREF="r11217.htm" 208>ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT</A 209> -- Query or select the current video input</DT 210><DT 211><A 212HREF="r11285.htm" 213>ioctl VIDIOC_G_JPEGCOMP, VIDIOC_S_JPEGCOMP</A 214> -- </DT 215><DT 216><A 217HREF="r11430.htm" 218>ioctl VIDIOC_G_MODULATOR, VIDIOC_S_MODULATOR</A 219> -- Get or set modulator attributes</DT 220><DT 221><A 222HREF="r11612.htm" 223>ioctl VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT</A 224> -- Query or select the current video output</DT 225><DT 226><A 227HREF="r11680.htm" 228>ioctl VIDIOC_G_PARM, VIDIOC_S_PARM</A 229> -- Get or set streaming parameters</DT 230><DT 231><A 232HREF="r11946.htm" 233>ioctl VIDIOC_G_PRIORITY, VIDIOC_S_PRIORITY</A 234> -- Query or request the access priority associated with a 235file descriptor</DT 236><DT 237><A 238HREF="r12051.htm" 239>ioctl VIDIOC_G_SLICED_VBI_CAP</A 240> -- Query sliced VBI capabilities</DT 241><DT 242><A 243HREF="r12265.htm" 244>ioctl VIDIOC_G_STD, VIDIOC_S_STD</A 245> -- Query or select the video standard of the current input</DT 246><DT 247><A 248HREF="r12342.htm" 249>ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</A 250> -- Get or set tuner attributes</DT 251><DT 252><A 253HREF="r12784.htm" 254>ioctl VIDIOC_LOG_STATUS</A 255> -- Log driver status information</DT 256><DT 257><A 258HREF="r12816.htm" 259>ioctl VIDIOC_OVERLAY</A 260> -- Start or stop video overlay</DT 261><DT 262><A 263HREF="r12878.htm" 264>ioctl VIDIOC_QBUF, VIDIOC_DQBUF</A 265> -- Exchange a buffer with the driver</DT 266><DT 267><A 268HREF="r13022.htm" 269>ioctl VIDIOC_QUERYBUF</A 270> -- Query the status of a buffer</DT 271><DT 272><A 273HREF="r13105.htm" 274>ioctl VIDIOC_QUERYCAP</A 275> -- Query device capabilities</DT 276><DT 277><A 278HREF="r13317.htm" 279>ioctl VIDIOC_QUERYCTRL, VIDIOC_QUERYMENU</A 280> -- Enumerate controls and menu control items</DT 281><DT 282><A 283HREF="r13641.htm" 284>ioctl VIDIOC_QUERYSTD</A 285> -- Sense the video standard received by the current 286input</DT 287><DT 288><A 289HREF="r13696.htm" 290>ioctl VIDIOC_REQBUFS</A 291> -- Initiate Memory Mapping or User Pointer I/O</DT 292><DT 293><A 294HREF="r13817.htm" 295>ioctl VIDIOC_STREAMON, VIDIOC_STREAMOFF</A 296> -- Start or stop streaming I/O</DT 297><DT 298><A 299HREF="r13889.htm" 300>V4L2 mmap()</A 301> -- Map device memory into application address space</DT 302><DT 303><A 304HREF="r14037.htm" 305>V4L2 munmap()</A 306> -- Unmap device memory</DT 307><DT 308><A 309HREF="r14090.htm" 310>V4L2 open()</A 311> -- Open a V4L2 device</DT 312><DT 313><A 314HREF="r14169.htm" 315>V4L2 poll()</A 316> -- Wait for some event on a file descriptor</DT 317><DT 318><A 319HREF="r14264.htm" 320>V4L2 read()</A 321> -- Read from a V4L2 device</DT 322><DT 323><A 324HREF="r14390.htm" 325>V4L2 select()</A 326> -- Synchronous I/O multiplexing</DT 327><DT 328><A 329HREF="r14496.htm" 330>V4L2 write()</A 331> -- Write to a V4L2 device</DT 332></DL 333></DIV 334></DIV 335></DIV 336><DIV 337CLASS="NAVFOOTER" 338><HR 339ALIGN="LEFT" 340WIDTH="100%"><TABLE 341SUMMARY="Footer navigation table" 342WIDTH="100%" 343BORDER="0" 344CELLPADDING="0" 345CELLSPACING="0" 346><TR 347><TD 348WIDTH="33%" 349ALIGN="left" 350VALIGN="top" 351><A 352HREF="x7607.htm" 353ACCESSKEY="P" 354>Prev</A 355></TD 356><TD 357WIDTH="34%" 358ALIGN="center" 359VALIGN="top" 360><A 361HREF="book1.htm" 362ACCESSKEY="H" 363>Home</A 364></TD 365><TD 366WIDTH="33%" 367ALIGN="right" 368VALIGN="top" 369><A 370HREF="r7626.htm" 371ACCESSKEY="N" 372>Next</A 373></TD 374></TR 375><TR 376><TD 377WIDTH="33%" 378ALIGN="left" 379VALIGN="top" 380>RDS Interface</TD 381><TD 382WIDTH="34%" 383ALIGN="center" 384VALIGN="top" 385> </TD 386><TD 387WIDTH="33%" 388ALIGN="right" 389VALIGN="top" 390>V4L2 close()</TD 391></TR 392></TABLE 393></DIV 394></BODY 395></HTML 396> 397