Documentation/DocBook/media/v4l/v4l2.xml

   1  <partinfo>
   2     <authorgroup>
   3       <author>
   4         <firstname>Michael</firstname>
   5         <surname>Schimek</surname>
   6         <othername role="mi">H</othername>
   7         <affiliation>
   8           <address>
   9             <email>mschimek@gmx.at</email>
  10           </address>
  11         </affiliation>
  12       </author>
  13
  14       <author>
  15         <firstname>Bill</firstname>
  16         <surname>Dirks</surname>
  17         <!-- Commented until Bill opts in to be spammed.
  18         <affiliation>
  19           <address>
  20             <email>bill@thedirks.org</email>
  21           </address>
  22         </affiliation> -->
  23         <contrib>Original author of the V4L2 API and
  24 documentation.</contrib>
  25       </author>
  26
  27       <author>
  28         <firstname>Hans</firstname>
  29         <surname>Verkuil</surname>
  30         <contrib>Designed and documented the VIDIOC_LOG_STATUS ioctl,
  31 the extended control ioctls, major parts of the sliced VBI API, the
  32 MPEG encoder and decoder APIs and the DV Timings API.</contrib>
  33         <affiliation>
  34           <address>
  35             <email>hverkuil@xs4all.nl</email>
  36           </address>
  37         </affiliation>
  38       </author>
  39
  40       <author>
  41         <firstname>Martin</firstname>
  42         <surname>Rubli</surname>
  43         <!--
  44         <affiliation>
  45           <address>
  46             <email>martin_rubli@logitech.com</email>
  47           </address>
  48         </affiliation> -->
  49         <contrib>Designed and documented the VIDIOC_ENUM_FRAMESIZES
  50 and VIDIOC_ENUM_FRAMEINTERVALS ioctls.</contrib>
  51       </author>
  52
  53       <author>
  54         <firstname>Andy</firstname>
  55         <surname>Walls</surname>
  56         <contrib>Documented the fielded V4L2_MPEG_STREAM_VBI_FMT_IVTV
  57 MPEG stream embedded, sliced VBI data format in this specification.
  58 </contrib>
  59         <affiliation>
  60           <address>
  61             <email>awalls@md.metrocast.net</email>
  62           </address>
  63         </affiliation>
  64       </author>
  65
  66       <author>
  67         <firstname>Mauro</firstname>
  68         <surname>Carvalho Chehab</surname>
  69         <contrib>Documented libv4l, designed and added v4l2grab example,
  70 Remote Controller chapter.</contrib>
  71         <affiliation>
  72           <address>
  73             <email>mchehab@redhat.com</email>
  74           </address>
  75         </affiliation>
  76       </author>
  77
  78       <author>
  79         <firstname>Muralidharan</firstname>
  80         <surname>Karicheri</surname>
  81         <contrib>Documented the Digital Video timings API.</contrib>
  82         <affiliation>
  83           <address>
  84             <email>m-karicheri2@ti.com</email>
  85           </address>
  86         </affiliation>
  87       </author>
  88
  89       <author>
  90         <firstname>Pawel</firstname>
  91         <surname>Osciak</surname>
  92         <contrib>Designed and documented the multi-planar API.</contrib>
  93         <affiliation>
  94           <address>
  95             <email>pawel AT osciak.com</email>
  96           </address>
  97         </affiliation>
  98       </author>
  99
 100       <author>
 101         <firstname>Sakari</firstname>
 102         <surname>Ailus</surname>
 103         <contrib>Subdev selections API.</contrib>
 104         <affiliation>
 105           <address>
 106             <email>sakari.ailus@iki.fi</email>
 107           </address>
 108         </affiliation>
 109       </author>
 110     </authorgroup>
 111
 112     <copyright>
 113       <year>1999</year>
 114       <year>2000</year>
 115       <year>2001</year>
 116       <year>2002</year>
 117       <year>2003</year>
 118       <year>2004</year>
 119       <year>2005</year>
 120       <year>2006</year>
 121       <year>2007</year>
 122       <year>2008</year>
 123       <year>2009</year>
 124       <year>2010</year>
 125       <year>2011</year>
 126       <year>2012</year>
 127       <year>2013</year>
 128       <holder>Bill Dirks, Michael H. Schimek, Hans Verkuil, Martin
 129 Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab,
 130         Pawel Osciak</holder>
 131     </copyright>
 132     <legalnotice>
 133     <para>Except when explicitly stated as GPL, programming examples within
 134             this part can be used and distributed without restrictions.</para>
 135     </legalnotice>
 136     <revhistory>
 137       <!-- Put document revisions here, newest first. -->
 138       <!-- API revisions (changes and additions of defines, enums,
 139 structs, ioctls) must be noted in more detail in the history chapter
 140 (compat.xml), along with the possible impact on existing drivers and
 141 applications. -->
 142
 143       <revision>
 144         <revnumber>3.10</revnumber>
 145         <date>2013-03-25</date>
 146         <authorinitials>hv</authorinitials>
 147         <revremark>Remove obsolete and unused DV_PRESET ioctls:
 148         VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET, VIDIOC_QUERY_DV_PRESET and
 149         VIDIOC_ENUM_DV_PRESET. Remove the related v4l2_input/output capability
 150         flags V4L2_IN_CAP_PRESETS and V4L2_OUT_CAP_PRESETS. Added VIDIOC_DBG_G_CHIP_INFO.
 151         </revremark>
 152       </revision>
 153
 154       <revision>
 155         <revnumber>3.9</revnumber>
 156         <date>2012-12-03</date>
 157         <authorinitials>sa, sn</authorinitials>
 158         <revremark>Added timestamp types to v4l2_buffer.
 159         Added V4L2_EVENT_CTRL_CH_RANGE control event changes flag.
 160         </revremark>
 161       </revision>
 162
 163       <revision>
 164         <revnumber>3.6</revnumber>
 165         <date>2012-07-02</date>
 166         <authorinitials>hv</authorinitials>
 167         <revremark>Added VIDIOC_ENUM_FREQ_BANDS.
 168         </revremark>
 169       </revision>
 170
 171       <revision>
 172         <revnumber>3.5</revnumber>
 173         <date>2012-05-07</date>
 174         <authorinitials>sa, sn, hv</authorinitials>
 175         <revremark>Added V4L2_CTRL_TYPE_INTEGER_MENU and V4L2 subdev
 176             selections API. Improved the description of V4L2_CID_COLORFX
 177             control, added V4L2_CID_COLORFX_CBCR control.
 178             Added camera controls V4L2_CID_AUTO_EXPOSURE_BIAS,
 179             V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE, V4L2_CID_IMAGE_STABILIZATION,
 180             V4L2_CID_ISO_SENSITIVITY, V4L2_CID_ISO_SENSITIVITY_AUTO,
 181             V4L2_CID_EXPOSURE_METERING, V4L2_CID_SCENE_MODE,
 182             V4L2_CID_3A_LOCK, V4L2_CID_AUTO_FOCUS_START,
 183             V4L2_CID_AUTO_FOCUS_STOP, V4L2_CID_AUTO_FOCUS_STATUS
 184             and V4L2_CID_AUTO_FOCUS_RANGE.
 185             Added VIDIOC_ENUM_DV_TIMINGS, VIDIOC_QUERY_DV_TIMINGS and
 186             VIDIOC_DV_TIMINGS_CAP.
 187         </revremark>
 188       </revision>
 189
 190       <revision>
 191         <revnumber>3.4</revnumber>
 192         <date>2012-01-25</date>
 193         <authorinitials>sn</authorinitials>
 194         <revremark>Added <link linkend="jpeg-controls">JPEG compression
 195             control class.</link>
 196         </revremark>
 197       </revision>
 198
 199       <revision>
 200         <revnumber>3.3</revnumber>
 201         <date>2012-01-11</date>
 202         <authorinitials>hv</authorinitials>
 203         <revremark>Added device_caps field to struct v4l2_capabilities.</revremark>
 204       </revision>
 205
 206       <revision>
 207         <revnumber>3.2</revnumber>
 208         <date>2011-08-26</date>
 209         <authorinitials>hv</authorinitials>
 210         <revremark>Added V4L2_CTRL_FLAG_VOLATILE.</revremark>
 211       </revision>
 212
 213       <revision>
 214         <revnumber>3.1</revnumber>
 215         <date>2011-06-27</date>
 216         <authorinitials>mcc, po, hv</authorinitials>
 217         <revremark>Documented that VIDIOC_QUERYCAP now returns a per-subsystem version instead of a per-driver one.
 218                    Standardize an error code for invalid ioctl.
 219                    Added V4L2_CTRL_TYPE_BITMASK.</revremark>
 220       </revision>
 221
 222       <revision>
 223         <revnumber>2.6.39</revnumber>
 224         <date>2011-03-01</date>
 225         <authorinitials>mcc, po</authorinitials>
 226         <revremark>Removed VIDIOC_*_OLD from videodev2.h header and update it to reflect latest changes. Added the <link linkend="planar-apis">multi-planar API</link>.</revremark>
 227       </revision>
 228
 229       <revision>
 230         <revnumber>2.6.37</revnumber>
 231         <date>2010-08-06</date>
 232         <authorinitials>hv</authorinitials>
 233         <revremark>Removed obsolete vtx (videotext) API.</revremark>
 234       </revision>
 235
 236       <revision>
 237         <revnumber>2.6.33</revnumber>
 238         <date>2009-12-03</date>
 239         <authorinitials>mk</authorinitials>
 240         <revremark>Added documentation for the Digital Video timings API.</revremark>
 241       </revision>
 242
 243       <revision>
 244         <revnumber>2.6.32</revnumber>
 245         <date>2009-08-31</date>
 246         <authorinitials>mcc</authorinitials>
 247         <revremark>Now, revisions will match the kernel version where
 248 the V4L2 API changes will be used by the Linux Kernel.
 249 Also added Remote Controller chapter.</revremark>
 250       </revision>
 251
 252       <revision>
 253         <revnumber>0.29</revnumber>
 254         <date>2009-08-26</date>
 255         <authorinitials>ev</authorinitials>
 256         <revremark>Added documentation for string controls and for FM Transmitter controls.</revremark>
 257       </revision>
 258
 259       <revision>
 260         <revnumber>0.28</revnumber>
 261         <date>2009-08-26</date>
 262         <authorinitials>gl</authorinitials>
 263         <revremark>Added V4L2_CID_BAND_STOP_FILTER documentation.</revremark>
 264       </revision>
 265
 266       <revision>
 267         <revnumber>0.27</revnumber>
 268         <date>2009-08-15</date>
 269         <authorinitials>mcc</authorinitials>
 270         <revremark>Added libv4l and Remote Controller documentation;
 271 added v4l2grab and keytable application examples.</revremark>
 272       </revision>
 273
 274       <revision>
 275         <revnumber>0.26</revnumber>
 276         <date>2009-07-23</date>
 277         <authorinitials>hv</authorinitials>
 278         <revremark>Finalized the RDS capture API. Added modulator and RDS encoder
 279 capabilities. Added support for string controls.</revremark>
 280       </revision>
 281
 282       <revision>
 283         <revnumber>0.25</revnumber>
 284         <date>2009-01-18</date>
 285         <authorinitials>hv</authorinitials>
 286         <revremark>Added pixel formats VYUY, NV16 and NV61, and changed
 287 the debug ioctls VIDIOC_DBG_G/S_REGISTER and VIDIOC_DBG_G_CHIP_IDENT.
 288 Added camera controls V4L2_CID_ZOOM_ABSOLUTE, V4L2_CID_ZOOM_RELATIVE,
 289 V4L2_CID_ZOOM_CONTINUOUS and V4L2_CID_PRIVACY.</revremark>
 290       </revision>
 291
 292       <revision>
 293         <revnumber>0.24</revnumber>
 294         <date>2008-03-04</date>
 295         <authorinitials>mhs</authorinitials>
 296         <revremark>Added pixel formats Y16 and SBGGR16, new controls
 297 and a camera controls class. Removed VIDIOC_G/S_MPEGCOMP.</revremark>
 298       </revision>
 299
 300       <revision>
 301         <revnumber>0.23</revnumber>
 302         <date>2007-08-30</date>
 303         <authorinitials>mhs</authorinitials>
 304         <revremark>Fixed a typo in VIDIOC_DBG_G/S_REGISTER.
 305 Clarified the byte order of packed pixel formats.</revremark>
 306       </revision>
 307
 308       <revision>
 309         <revnumber>0.22</revnumber>
 310         <date>2007-08-29</date>
 311         <authorinitials>mhs</authorinitials>
 312         <revremark>Added the Video Output Overlay interface, new MPEG
 313 controls, V4L2_FIELD_INTERLACED_TB and V4L2_FIELD_INTERLACED_BT,
 314 VIDIOC_DBG_G/S_REGISTER, VIDIOC_(TRY_)ENCODER_CMD,
 315 VIDIOC_G_CHIP_IDENT, VIDIOC_G_ENC_INDEX, new pixel formats.
 316 Clarifications in the cropping chapter, about RGB pixel formats, the
 317 mmap(), poll(), select(), read() and write() functions. Typographical
 318 fixes.</revremark>
 319       </revision>
 320
 321       <revision>
 322         <revnumber>0.21</revnumber>
 323         <date>2006-12-19</date>
 324         <authorinitials>mhs</authorinitials>
 325         <revremark>Fixed a link in the VIDIOC_G_EXT_CTRLS section.</revremark>
 326       </revision>
 327
 328       <revision>
 329         <revnumber>0.20</revnumber>
 330         <date>2006-11-24</date>
 331         <authorinitials>mhs</authorinitials>
 332         <revremark>Clarified the purpose of the audioset field in
 333 struct v4l2_input and v4l2_output.</revremark>
 334       </revision>
 335
 336       <revision>
 337         <revnumber>0.19</revnumber>
 338         <date>2006-10-19</date>
 339         <authorinitials>mhs</authorinitials>
 340         <revremark>Documented V4L2_PIX_FMT_RGB444.</revremark>
 341       </revision>
 342
 343       <revision>
 344         <revnumber>0.18</revnumber>
 345         <date>2006-10-18</date>
 346         <authorinitials>mhs</authorinitials>
 347         <revremark>Added the description of extended controls by Hans
 348 Verkuil. Linked V4L2_PIX_FMT_MPEG to V4L2_CID_MPEG_STREAM_TYPE.</revremark>
 349       </revision>
 350
 351       <revision>
 352         <revnumber>0.17</revnumber>
 353         <date>2006-10-12</date>
 354         <authorinitials>mhs</authorinitials>
 355         <revremark>Corrected V4L2_PIX_FMT_HM12 description.</revremark>
 356       </revision>
 357
 358       <revision>
 359         <revnumber>0.16</revnumber>
 360         <date>2006-10-08</date>
 361         <authorinitials>mhs</authorinitials>
 362         <revremark>VIDIOC_ENUM_FRAMESIZES and
 363 VIDIOC_ENUM_FRAMEINTERVALS are now part of the API.</revremark>
 364       </revision>
 365
 366       <revision>
 367         <revnumber>0.15</revnumber>
 368         <date>2006-09-23</date>
 369         <authorinitials>mhs</authorinitials>
 370         <revremark>Cleaned up the bibliography, added BT.653 and
 371 BT.1119. capture.c/start_capturing() for user pointer I/O did not
 372 initialize the buffer index. Documented the V4L MPEG and MJPEG
 373 VID_TYPEs and V4L2_PIX_FMT_SBGGR8. Updated the list of reserved pixel
 374 formats. See the history chapter for API changes.</revremark>
 375       </revision>
 376
 377       <revision>
 378         <revnumber>0.14</revnumber>
 379         <date>2006-09-14</date>
 380         <authorinitials>mr</authorinitials>
 381         <revremark>Added VIDIOC_ENUM_FRAMESIZES and
 382 VIDIOC_ENUM_FRAMEINTERVALS proposal for frame format enumeration of
 383 digital devices.</revremark>
 384       </revision>
 385
 386       <revision>
 387         <revnumber>0.13</revnumber>
 388         <date>2006-04-07</date>
 389         <authorinitials>mhs</authorinitials>
 390         <revremark>Corrected the description of struct v4l2_window
 391 clips. New V4L2_STD_ and V4L2_TUNER_MODE_LANG1_LANG2
 392 defines.</revremark>
 393       </revision>
 394
 395       <revision>
 396         <revnumber>0.12</revnumber>
 397         <date>2006-02-03</date>
 398         <authorinitials>mhs</authorinitials>
 399         <revremark>Corrected the description of struct
 400 v4l2_captureparm and v4l2_outputparm.</revremark>
 401       </revision>
 402
 403       <revision>
 404         <revnumber>0.11</revnumber>
 405         <date>2006-01-27</date>
 406         <authorinitials>mhs</authorinitials>
 407         <revremark>Improved the description of struct
 408 v4l2_tuner.</revremark>
 409       </revision>
 410
 411       <revision>
 412         <revnumber>0.10</revnumber>
 413         <date>2006-01-10</date>
 414         <authorinitials>mhs</authorinitials>
 415         <revremark>VIDIOC_G_INPUT and VIDIOC_S_PARM
 416 clarifications.</revremark>
 417       </revision>
 418
 419       <revision>
 420         <revnumber>0.9</revnumber>
 421         <date>2005-11-27</date>
 422         <authorinitials>mhs</authorinitials>
 423         <revremark>Improved the 525 line numbering diagram. Hans
 424 Verkuil and I rewrote the sliced VBI section. He also contributed a
 425 VIDIOC_LOG_STATUS page. Fixed VIDIOC_S_STD call in the video standard
 426 selection example. Various updates.</revremark>
 427       </revision>
 428
 429       <revision>
 430         <revnumber>0.8</revnumber>
 431         <date>2004-10-04</date>
 432         <authorinitials>mhs</authorinitials>
 433         <revremark>Somehow a piece of junk slipped into the capture
 434 example, removed.</revremark>
 435       </revision>
 436
 437       <revision>
 438         <revnumber>0.7</revnumber>
 439         <date>2004-09-19</date>
 440         <authorinitials>mhs</authorinitials>
 441         <revremark>Fixed video standard selection, control
 442 enumeration, downscaling and aspect example. Added read and user
 443 pointer i/o to video capture example.</revremark>
 444       </revision>
 445
 446       <revision>
 447         <revnumber>0.6</revnumber>
 448         <date>2004-08-01</date>
 449         <authorinitials>mhs</authorinitials>
 450         <revremark>v4l2_buffer changes, added video capture example,
 451 various corrections.</revremark>
 452       </revision>
 453
 454       <revision>
 455         <revnumber>0.5</revnumber>
 456         <date>2003-11-05</date>
 457         <authorinitials>mhs</authorinitials>
 458         <revremark>Pixel format erratum.</revremark>
 459       </revision>
 460
 461       <revision>
 462         <revnumber>0.4</revnumber>
 463         <date>2003-09-17</date>
 464         <authorinitials>mhs</authorinitials>
 465         <revremark>Corrected source and Makefile to generate a PDF.
 466 SGML fixes. Added latest API changes. Closed gaps in the history
 467 chapter.</revremark>
 468       </revision>
 469
 470       <revision>
 471         <revnumber>0.3</revnumber>
 472         <date>2003-02-05</date>
 473         <authorinitials>mhs</authorinitials>
 474         <revremark>Another draft, more corrections.</revremark>
 475       </revision>
 476
 477       <revision>
 478         <revnumber>0.2</revnumber>
 479         <date>2003-01-15</date>
 480         <authorinitials>mhs</authorinitials>
 481         <revremark>Second draft, with corrections pointed out by Gerd
 482 Knorr.</revremark>
 483       </revision>
 484
 485       <revision>
 486         <revnumber>0.1</revnumber>
 487         <date>2002-12-01</date>
 488         <authorinitials>mhs</authorinitials>
 489         <revremark>First draft, based on documentation by Bill Dirks
 490 and discussions on the V4L mailing list.</revremark>
 491       </revision>
 492     </revhistory>
 493 </partinfo>
 494
 495 <title>Video for Linux Two API Specification</title>
 496  <subtitle>Revision 3.9</subtitle>
 497
 498   <chapter id="common">
 499     &sub-common;
 500   </chapter>
 501
 502   <chapter id="pixfmt">
 503     &sub-pixfmt;
 504   </chapter>
 505
 506   <chapter id="io">
 507     &sub-io;
 508   </chapter>
 509
 510   <chapter id="devices">
 511     <title>Interfaces</title>
 512
 513     <section id="capture"> &sub-dev-capture; </section>
 514     <section id="overlay"> &sub-dev-overlay; </section>
 515     <section id="output"> &sub-dev-output; </section>
 516     <section id="osd"> &sub-dev-osd; </section>
 517     <section id="codec"> &sub-dev-codec; </section>
 518     <section id="effect"> &sub-dev-effect; </section>
 519     <section id="raw-vbi"> &sub-dev-raw-vbi; </section>
 520     <section id="sliced"> &sub-dev-sliced-vbi; </section>
 521     <section id="ttx"> &sub-dev-teletext; </section>
 522     <section id="radio"> &sub-dev-radio; </section>
 523     <section id="rds"> &sub-dev-rds; </section>
 524     <section id="event"> &sub-dev-event; </section>
 525     <section id="subdev"> &sub-dev-subdev; </section>
 526   </chapter>
 527
 528   <chapter id="driver">
 529           &sub-driver;
 530   </chapter>
 531
 532   <chapter id="libv4l">
 533           &sub-libv4l;
 534   </chapter>
 535
 536   <chapter id="compat">
 537           &sub-compat;
 538   </chapter>
 539
 540   <appendix id="user-func">
 541   <title>Function Reference</title>
 542
 543     <!-- Keep this alphabetically sorted. -->
 544
 545     &sub-close;
 546     &sub-ioctl;
 547     <!-- All ioctls go here. -->
 548     &sub-create-bufs;
 549     &sub-cropcap;
 550     &sub-dbg-g-chip-ident;
 551     &sub-dbg-g-chip-info;
 552     &sub-dbg-g-register;
 553     &sub-decoder-cmd;
 554     &sub-dqevent;
 555     &sub-dv-timings-cap;
 556     &sub-encoder-cmd;
 557     &sub-enumaudio;
 558     &sub-enumaudioout;
 559     &sub-enum-dv-timings;
 560     &sub-enum-fmt;
 561     &sub-enum-framesizes;
 562     &sub-enum-frameintervals;
 563     &sub-enum-freq-bands;
 564     &sub-enuminput;
 565     &sub-enumoutput;
 566     &sub-enumstd;
 567     &sub-expbuf;
 568     &sub-g-audio;
 569     &sub-g-audioout;
 570     &sub-g-crop;
 571     &sub-g-ctrl;
 572     &sub-g-dv-timings;
 573     &sub-g-enc-index;
 574     &sub-g-ext-ctrls;
 575     &sub-g-fbuf;
 576     &sub-g-fmt;
 577     &sub-g-frequency;
 578     &sub-g-input;
 579     &sub-g-jpegcomp;
 580     &sub-g-modulator;
 581     &sub-g-output;
 582     &sub-g-parm;
 583     &sub-g-priority;
 584     &sub-g-selection;
 585     &sub-g-sliced-vbi-cap;
 586     &sub-g-std;
 587     &sub-g-tuner;
 588     &sub-log-status;
 589     &sub-overlay;
 590     &sub-prepare-buf;
 591     &sub-qbuf;
 592     &sub-querybuf;
 593     &sub-querycap;
 594     &sub-queryctrl;
 595     &sub-query-dv-timings;
 596     &sub-querystd;
 597     &sub-reqbufs;
 598     &sub-s-hw-freq-seek;
 599     &sub-streamon;
 600     &sub-subdev-enum-frame-interval;
 601     &sub-subdev-enum-frame-size;
 602     &sub-subdev-enum-mbus-code;
 603     &sub-subdev-g-crop;
 604     &sub-subdev-g-edid;
 605     &sub-subdev-g-fmt;
 606     &sub-subdev-g-frame-interval;
 607     &sub-subdev-g-selection;
 608     &sub-subscribe-event;
 609     <!-- End of ioctls. -->
 610     &sub-mmap;
 611     &sub-munmap;
 612     &sub-open;
 613     &sub-poll;
 614     &sub-read;
 615     &sub-select;
 616     &sub-write;
 617   </appendix>
 618
 619   <appendix>
 620     <title>Common definitions for V4L2 and V4L2 subdev interfaces</title>
 621       &sub-selections-common;
 622   </appendix>
 623
 624   <appendix id="videodev">
 625     <title>Video For Linux Two Header File</title>
 626     &sub-videodev2-h;
 627   </appendix>
 628
 629   <appendix id="capture-example">
 630     <title>Video Capture Example</title>
 631     &sub-capture-c;
 632   </appendix>
 633
 634   <appendix id="v4l2grab-example">
 635     <title>Video Grabber example using libv4l</title>
 636     <para>This program demonstrates how to grab V4L2 images in ppm format by
 637 using libv4l handlers. The advantage is that this grabber can potentially work
 638 with any V4L2 driver.</para>
 639     &sub-v4l2grab-c;
 640   </appendix>
 641
 642   &sub-media-indices;
 643
 644   &sub-biblio;
 645