|  | <partinfo> | 
|  | <authorgroup> | 
|  | <author> | 
|  | <firstname>Michael</firstname> | 
|  | <surname>Schimek</surname> | 
|  | <othername role="mi">H</othername> | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>mschimek@gmx.at</email> | 
|  | </address> | 
|  | </affiliation> | 
|  | </author> | 
|  |  | 
|  | <author> | 
|  | <firstname>Bill</firstname> | 
|  | <surname>Dirks</surname> | 
|  | <!-- Commented until Bill opts in to be spammed. | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>bill@thedirks.org</email> | 
|  | </address> | 
|  | </affiliation> --> | 
|  | <contrib>Original author of the V4L2 API and | 
|  | documentation.</contrib> | 
|  | </author> | 
|  |  | 
|  | <author> | 
|  | <firstname>Hans</firstname> | 
|  | <surname>Verkuil</surname> | 
|  | <contrib>Designed and documented the VIDIOC_LOG_STATUS ioctl, | 
|  | the extended control ioctls and major parts of the sliced VBI | 
|  | API.</contrib> | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>hverkuil@xs4all.nl</email> | 
|  | </address> | 
|  | </affiliation> | 
|  | </author> | 
|  |  | 
|  | <author> | 
|  | <firstname>Martin</firstname> | 
|  | <surname>Rubli</surname> | 
|  | <!-- | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>martin_rubli@logitech.com</email> | 
|  | </address> | 
|  | </affiliation> --> | 
|  | <contrib>Designed and documented the VIDIOC_ENUM_FRAMESIZES | 
|  | and VIDIOC_ENUM_FRAMEINTERVALS ioctls.</contrib> | 
|  | </author> | 
|  |  | 
|  | <author> | 
|  | <firstname>Andy</firstname> | 
|  | <surname>Walls</surname> | 
|  | <contrib>Documented the fielded V4L2_MPEG_STREAM_VBI_FMT_IVTV | 
|  | MPEG stream embedded, sliced VBI data format in this specification. | 
|  | </contrib> | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>awalls@md.metrocast.net</email> | 
|  | </address> | 
|  | </affiliation> | 
|  | </author> | 
|  |  | 
|  | <author> | 
|  | <firstname>Mauro</firstname> | 
|  | <surname>Carvalho Chehab</surname> | 
|  | <contrib>Documented libv4l, designed and added v4l2grab example, | 
|  | Remote Controller chapter.</contrib> | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>mchehab@redhat.com</email> | 
|  | </address> | 
|  | </affiliation> | 
|  | </author> | 
|  |  | 
|  | <author> | 
|  | <firstname>Muralidharan</firstname> | 
|  | <surname>Karicheri</surname> | 
|  | <contrib>Documented the Digital Video timings API.</contrib> | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>m-karicheri2@ti.com</email> | 
|  | </address> | 
|  | </affiliation> | 
|  | </author> | 
|  |  | 
|  | <author> | 
|  | <firstname>Pawel</firstname> | 
|  | <surname>Osciak</surname> | 
|  | <contrib>Designed and documented the multi-planar API.</contrib> | 
|  | <affiliation> | 
|  | <address> | 
|  | <email>pawel AT osciak.com</email> | 
|  | </address> | 
|  | </affiliation> | 
|  | </author> | 
|  | </authorgroup> | 
|  |  | 
|  | <copyright> | 
|  | <year>1999</year> | 
|  | <year>2000</year> | 
|  | <year>2001</year> | 
|  | <year>2002</year> | 
|  | <year>2003</year> | 
|  | <year>2004</year> | 
|  | <year>2005</year> | 
|  | <year>2006</year> | 
|  | <year>2007</year> | 
|  | <year>2008</year> | 
|  | <year>2009</year> | 
|  | <year>2010</year> | 
|  | <year>2011</year> | 
|  | <holder>Bill Dirks, Michael H. Schimek, Hans Verkuil, Martin | 
|  | Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab, | 
|  | Pawel Osciak</holder> | 
|  | </copyright> | 
|  | <legalnotice> | 
|  | <para>Except when explicitly stated as GPL, programming examples within | 
|  | this part can be used and distributed without restrictions.</para> | 
|  | </legalnotice> | 
|  | <revhistory> | 
|  | <!-- Put document revisions here, newest first. --> | 
|  | <!-- API revisions (changes and additions of defines, enums, | 
|  | structs, ioctls) must be noted in more detail in the history chapter | 
|  | (compat.xml), along with the possible impact on existing drivers and | 
|  | applications. --> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>3.2</revnumber> | 
|  | <date>2011-08-26</date> | 
|  | <authorinitials>hv</authorinitials> | 
|  | <revremark>Added V4L2_CTRL_FLAG_VOLATILE.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>3.1</revnumber> | 
|  | <date>2011-06-27</date> | 
|  | <authorinitials>mcc, po, hv</authorinitials> | 
|  | <revremark>Documented that VIDIOC_QUERYCAP now returns a per-subsystem version instead of a per-driver one. | 
|  | Standardize an error code for invalid ioctl. | 
|  | Added V4L2_CTRL_TYPE_BITMASK.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>2.6.39</revnumber> | 
|  | <date>2011-03-01</date> | 
|  | <authorinitials>mcc, po</authorinitials> | 
|  | <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> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>2.6.37</revnumber> | 
|  | <date>2010-08-06</date> | 
|  | <authorinitials>hv</authorinitials> | 
|  | <revremark>Removed obsolete vtx (videotext) API.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>2.6.33</revnumber> | 
|  | <date>2009-12-03</date> | 
|  | <authorinitials>mk</authorinitials> | 
|  | <revremark>Added documentation for the Digital Video timings API.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>2.6.32</revnumber> | 
|  | <date>2009-08-31</date> | 
|  | <authorinitials>mcc</authorinitials> | 
|  | <revremark>Now, revisions will match the kernel version where | 
|  | the V4L2 API changes will be used by the Linux Kernel. | 
|  | Also added Remote Controller chapter.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.29</revnumber> | 
|  | <date>2009-08-26</date> | 
|  | <authorinitials>ev</authorinitials> | 
|  | <revremark>Added documentation for string controls and for FM Transmitter controls.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.28</revnumber> | 
|  | <date>2009-08-26</date> | 
|  | <authorinitials>gl</authorinitials> | 
|  | <revremark>Added V4L2_CID_BAND_STOP_FILTER documentation.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.27</revnumber> | 
|  | <date>2009-08-15</date> | 
|  | <authorinitials>mcc</authorinitials> | 
|  | <revremark>Added libv4l and Remote Controller documentation; | 
|  | added v4l2grab and keytable application examples.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.26</revnumber> | 
|  | <date>2009-07-23</date> | 
|  | <authorinitials>hv</authorinitials> | 
|  | <revremark>Finalized the RDS capture API. Added modulator and RDS encoder | 
|  | capabilities. Added support for string controls.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.25</revnumber> | 
|  | <date>2009-01-18</date> | 
|  | <authorinitials>hv</authorinitials> | 
|  | <revremark>Added pixel formats VYUY, NV16 and NV61, and changed | 
|  | the debug ioctls VIDIOC_DBG_G/S_REGISTER and VIDIOC_DBG_G_CHIP_IDENT. | 
|  | Added camera controls V4L2_CID_ZOOM_ABSOLUTE, V4L2_CID_ZOOM_RELATIVE, | 
|  | V4L2_CID_ZOOM_CONTINUOUS and V4L2_CID_PRIVACY.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.24</revnumber> | 
|  | <date>2008-03-04</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Added pixel formats Y16 and SBGGR16, new controls | 
|  | and a camera controls class. Removed VIDIOC_G/S_MPEGCOMP.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.23</revnumber> | 
|  | <date>2007-08-30</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Fixed a typo in VIDIOC_DBG_G/S_REGISTER. | 
|  | Clarified the byte order of packed pixel formats.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.22</revnumber> | 
|  | <date>2007-08-29</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Added the Video Output Overlay interface, new MPEG | 
|  | controls, V4L2_FIELD_INTERLACED_TB and V4L2_FIELD_INTERLACED_BT, | 
|  | VIDIOC_DBG_G/S_REGISTER, VIDIOC_(TRY_)ENCODER_CMD, | 
|  | VIDIOC_G_CHIP_IDENT, VIDIOC_G_ENC_INDEX, new pixel formats. | 
|  | Clarifications in the cropping chapter, about RGB pixel formats, the | 
|  | mmap(), poll(), select(), read() and write() functions. Typographical | 
|  | fixes.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.21</revnumber> | 
|  | <date>2006-12-19</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Fixed a link in the VIDIOC_G_EXT_CTRLS section.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.20</revnumber> | 
|  | <date>2006-11-24</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Clarified the purpose of the audioset field in | 
|  | struct v4l2_input and v4l2_output.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.19</revnumber> | 
|  | <date>2006-10-19</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Documented V4L2_PIX_FMT_RGB444.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.18</revnumber> | 
|  | <date>2006-10-18</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Added the description of extended controls by Hans | 
|  | Verkuil. Linked V4L2_PIX_FMT_MPEG to V4L2_CID_MPEG_STREAM_TYPE.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.17</revnumber> | 
|  | <date>2006-10-12</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Corrected V4L2_PIX_FMT_HM12 description.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.16</revnumber> | 
|  | <date>2006-10-08</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>VIDIOC_ENUM_FRAMESIZES and | 
|  | VIDIOC_ENUM_FRAMEINTERVALS are now part of the API.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.15</revnumber> | 
|  | <date>2006-09-23</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Cleaned up the bibliography, added BT.653 and | 
|  | BT.1119. capture.c/start_capturing() for user pointer I/O did not | 
|  | initialize the buffer index. Documented the V4L MPEG and MJPEG | 
|  | VID_TYPEs and V4L2_PIX_FMT_SBGGR8. Updated the list of reserved pixel | 
|  | formats. See the history chapter for API changes.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.14</revnumber> | 
|  | <date>2006-09-14</date> | 
|  | <authorinitials>mr</authorinitials> | 
|  | <revremark>Added VIDIOC_ENUM_FRAMESIZES and | 
|  | VIDIOC_ENUM_FRAMEINTERVALS proposal for frame format enumeration of | 
|  | digital devices.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.13</revnumber> | 
|  | <date>2006-04-07</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Corrected the description of struct v4l2_window | 
|  | clips. New V4L2_STD_ and V4L2_TUNER_MODE_LANG1_LANG2 | 
|  | defines.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.12</revnumber> | 
|  | <date>2006-02-03</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Corrected the description of struct | 
|  | v4l2_captureparm and v4l2_outputparm.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.11</revnumber> | 
|  | <date>2006-01-27</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Improved the description of struct | 
|  | v4l2_tuner.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.10</revnumber> | 
|  | <date>2006-01-10</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>VIDIOC_G_INPUT and VIDIOC_S_PARM | 
|  | clarifications.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.9</revnumber> | 
|  | <date>2005-11-27</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Improved the 525 line numbering diagram. Hans | 
|  | Verkuil and I rewrote the sliced VBI section. He also contributed a | 
|  | VIDIOC_LOG_STATUS page. Fixed VIDIOC_S_STD call in the video standard | 
|  | selection example. Various updates.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.8</revnumber> | 
|  | <date>2004-10-04</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Somehow a piece of junk slipped into the capture | 
|  | example, removed.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.7</revnumber> | 
|  | <date>2004-09-19</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Fixed video standard selection, control | 
|  | enumeration, downscaling and aspect example. Added read and user | 
|  | pointer i/o to video capture example.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.6</revnumber> | 
|  | <date>2004-08-01</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>v4l2_buffer changes, added video capture example, | 
|  | various corrections.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.5</revnumber> | 
|  | <date>2003-11-05</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Pixel format erratum.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.4</revnumber> | 
|  | <date>2003-09-17</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Corrected source and Makefile to generate a PDF. | 
|  | SGML fixes. Added latest API changes. Closed gaps in the history | 
|  | chapter.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.3</revnumber> | 
|  | <date>2003-02-05</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Another draft, more corrections.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.2</revnumber> | 
|  | <date>2003-01-15</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>Second draft, with corrections pointed out by Gerd | 
|  | Knorr.</revremark> | 
|  | </revision> | 
|  |  | 
|  | <revision> | 
|  | <revnumber>0.1</revnumber> | 
|  | <date>2002-12-01</date> | 
|  | <authorinitials>mhs</authorinitials> | 
|  | <revremark>First draft, based on documentation by Bill Dirks | 
|  | and discussions on the V4L mailing list.</revremark> | 
|  | </revision> | 
|  | </revhistory> | 
|  | </partinfo> | 
|  |  | 
|  | <title>Video for Linux Two API Specification</title> | 
|  | <subtitle>Revision 3.2</subtitle> | 
|  |  | 
|  | <chapter id="common"> | 
|  | &sub-common; | 
|  | </chapter> | 
|  |  | 
|  | <chapter id="pixfmt"> | 
|  | &sub-pixfmt; | 
|  | </chapter> | 
|  |  | 
|  | <chapter id="io"> | 
|  | &sub-io; | 
|  | </chapter> | 
|  |  | 
|  | <chapter id="devices"> | 
|  | <title>Interfaces</title> | 
|  |  | 
|  | <section id="capture"> &sub-dev-capture; </section> | 
|  | <section id="overlay"> &sub-dev-overlay; </section> | 
|  | <section id="output"> &sub-dev-output; </section> | 
|  | <section id="osd"> &sub-dev-osd; </section> | 
|  | <section id="codec"> &sub-dev-codec; </section> | 
|  | <section id="effect"> &sub-dev-effect; </section> | 
|  | <section id="raw-vbi"> &sub-dev-raw-vbi; </section> | 
|  | <section id="sliced"> &sub-dev-sliced-vbi; </section> | 
|  | <section id="ttx"> &sub-dev-teletext; </section> | 
|  | <section id="radio"> &sub-dev-radio; </section> | 
|  | <section id="rds"> &sub-dev-rds; </section> | 
|  | <section id="event"> &sub-dev-event; </section> | 
|  | <section id="subdev"> &sub-dev-subdev; </section> | 
|  | </chapter> | 
|  |  | 
|  | <chapter id="driver"> | 
|  | &sub-driver; | 
|  | </chapter> | 
|  |  | 
|  | <chapter id="libv4l"> | 
|  | &sub-libv4l; | 
|  | </chapter> | 
|  |  | 
|  | <chapter id="compat"> | 
|  | &sub-compat; | 
|  | </chapter> | 
|  |  | 
|  | <appendix id="user-func"> | 
|  | <title>Function Reference</title> | 
|  |  | 
|  | <!-- Keep this alphabetically sorted. --> | 
|  |  | 
|  | &sub-close; | 
|  | &sub-ioctl; | 
|  | <!-- All ioctls go here. --> | 
|  | &sub-create-bufs; | 
|  | &sub-cropcap; | 
|  | &sub-dbg-g-chip-ident; | 
|  | &sub-dbg-g-register; | 
|  | &sub-dqevent; | 
|  | &sub-encoder-cmd; | 
|  | &sub-enumaudio; | 
|  | &sub-enumaudioout; | 
|  | &sub-enum-dv-presets; | 
|  | &sub-enum-fmt; | 
|  | &sub-enum-framesizes; | 
|  | &sub-enum-frameintervals; | 
|  | &sub-enuminput; | 
|  | &sub-enumoutput; | 
|  | &sub-enumstd; | 
|  | &sub-g-audio; | 
|  | &sub-g-audioout; | 
|  | &sub-g-crop; | 
|  | &sub-g-ctrl; | 
|  | &sub-g-dv-preset; | 
|  | &sub-g-dv-timings; | 
|  | &sub-g-enc-index; | 
|  | &sub-g-ext-ctrls; | 
|  | &sub-g-fbuf; | 
|  | &sub-g-fmt; | 
|  | &sub-g-frequency; | 
|  | &sub-g-input; | 
|  | &sub-g-jpegcomp; | 
|  | &sub-g-modulator; | 
|  | &sub-g-output; | 
|  | &sub-g-parm; | 
|  | &sub-g-priority; | 
|  | &sub-g-sliced-vbi-cap; | 
|  | &sub-g-std; | 
|  | &sub-g-tuner; | 
|  | &sub-log-status; | 
|  | &sub-overlay; | 
|  | &sub-qbuf; | 
|  | &sub-querybuf; | 
|  | &sub-querycap; | 
|  | &sub-queryctrl; | 
|  | &sub-query-dv-preset; | 
|  | &sub-querystd; | 
|  | &sub-prepare-buf; | 
|  | &sub-reqbufs; | 
|  | &sub-s-hw-freq-seek; | 
|  | &sub-streamon; | 
|  | &sub-subdev-enum-frame-interval; | 
|  | &sub-subdev-enum-frame-size; | 
|  | &sub-subdev-enum-mbus-code; | 
|  | &sub-subdev-g-crop; | 
|  | &sub-subdev-g-fmt; | 
|  | &sub-subdev-g-frame-interval; | 
|  | &sub-subscribe-event; | 
|  | <!-- End of ioctls. --> | 
|  | &sub-mmap; | 
|  | &sub-munmap; | 
|  | &sub-open; | 
|  | &sub-poll; | 
|  | &sub-read; | 
|  | &sub-select; | 
|  | &sub-write; | 
|  | </appendix> | 
|  |  | 
|  | <appendix id="videodev"> | 
|  | <title>Video For Linux Two Header File</title> | 
|  | &sub-videodev2-h; | 
|  | </appendix> | 
|  |  | 
|  | <appendix id="capture-example"> | 
|  | <title>Video Capture Example</title> | 
|  | &sub-capture-c; | 
|  | </appendix> | 
|  |  | 
|  | <appendix id="v4l2grab-example"> | 
|  | <title>Video Grabber example using libv4l</title> | 
|  | <para>This program demonstrates how to grab V4L2 images in ppm format by | 
|  | using libv4l handlers. The advantage is that this grabber can potentially work | 
|  | with any V4L2 driver.</para> | 
|  | &sub-v4l2grab-c; | 
|  | </appendix> | 
|  |  | 
|  | &sub-media-indices; | 
|  |  | 
|  | &sub-biblio; | 
|  |  |