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SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. include:: <isonum.txt> + +.. _v4l2spec: + +############################ +Part I - Video for Linux API +############################ + +This part describes the Video for Linux API version 2 (V4L2 API) specification. + +**Revision 4.5** + +.. only:: html + + .. class:: toc-title + + Table of Contents + +.. toctree:: + :numbered: + :maxdepth: 5 + + common + pixfmt + io + devices + libv4l + compat + user-func + common-defs + videodev + capture-example + v4l2grab-example + biblio + + +********************** +Revision and Copyright +********************** + +Authors, in alphabetical order: + +- Ailus, Sakari <sakari.ailus@iki.fi> + + - Subdev selections API. + +- Carvalho Chehab, Mauro <mchehab+samsung@kernel.org> + + - Documented libv4l, designed and added v4l2grab example, Remote Controller chapter. + +- Dirks, Bill + + - Original author of the V4L2 API and documentation. + +- Figa, Tomasz <tfiga@chromium.org> + + - Documented the memory-to-memory decoder interface. + - Documented the memory-to-memory encoder interface. + +- H Schimek, Michael <mschimek@gmx.at> + + - Original author of the V4L2 API and documentation. + +- Karicheri, Muralidharan <m-karicheri2@ti.com> + + - Documented the Digital Video timings API. + +- Osciak, Pawel <posciak@chromium.org> + + - Documented the memory-to-memory decoder interface. + - Documented the memory-to-memory encoder interface. + +- Osciak, Pawel <pawel@osciak.com> + + - Designed and documented the multi-planar API. + +- Palosaari, Antti <crope@iki.fi> + + - SDR API. + +- Ribalda, Ricardo + + - Introduce HSV formats and other minor changes. + +- Rubli, Martin + + - Designed and documented the VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS ioctls. + +- Walls, Andy <awalls@md.metrocast.net> + + - Documented the fielded V4L2_MPEG_STREAM_VBI_FMT_IVTV MPEG stream embedded, sliced VBI data format in this specification. + +- Verkuil, Hans <hverkuil@xs4all.nl> + + - Designed and documented the VIDIOC_LOG_STATUS ioctl, the extended control ioctls, major parts of the sliced VBI API, the MPEG encoder and decoder APIs and the DV Timings API. + +**Copyright** |copy| 1999-2018: Bill Dirks, Michael H. Schimek, Hans Verkuil, Martin Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab, Pawel Osciak, Sakari Ailus & Antti Palosaari, Tomasz Figa + +Except when explicitly stated as GPL, programming examples within this +part can be used and distributed without restrictions. + +**************** +Revision History +**************** + +:revision: 4.10 / 2016-07-15 (*rr*) + +Introduce HSV formats. + + +:revision: 4.5 / 2015-10-29 (*rr*) + +Extend VIDIOC_G_EXT_CTRLS;. Replace ctrl_class with a new union with +ctrl_class and which. Which is used to select the current value of the +control or the default value. + + +:revision: 4.4 / 2015-05-26 (*ap*) + +Renamed V4L2_TUNER_ADC to V4L2_TUNER_SDR. Added +V4L2_CID_RF_TUNER_RF_GAIN control. Added transmitter support for +Software Defined Radio (SDR) Interface. + + +:revision: 4.1 / 2015-02-13 (*mcc*) + +Fix documentation for media controller device nodes and add support for +DVB device nodes. Add support for Tuner sub-device. + + +:revision: 3.19 / 2014-12-05 (*hv*) + +Rewrote Colorspace chapter, added new enum +:c:type:`v4l2_ycbcr_encoding` and enum +:c:type:`v4l2_quantization` fields to struct +:c:type:`v4l2_pix_format`, struct +:c:type:`v4l2_pix_format_mplane` and struct +:c:type:`v4l2_mbus_framefmt`. + + +:revision: 3.17 / 2014-08-04 (*lp, hv*) + +Extended struct :c:type:`v4l2_pix_format`. Added +format flags. Added compound control types and VIDIOC_QUERY_EXT_CTRL. + + +:revision: 3.15 / 2014-02-03 (*hv, ap*) + +Update several sections of "Common API Elements": "Opening and Closing +Devices" "Querying Capabilities", "Application Priority", "Video Inputs +and Outputs", "Audio Inputs and Outputs" "Tuners and Modulators", "Video +Standards" and "Digital Video (DV) Timings". Added SDR API. + + +:revision: 3.14 / 2013-11-25 (*rr*) + +Set width and height as unsigned on v4l2_rect. + + +:revision: 3.11 / 2013-05-26 (*hv*) + +Remove obsolete VIDIOC_DBG_G_CHIP_IDENT ioctl. + + +:revision: 3.10 / 2013-03-25 (*hv*) + +Remove obsolete and unused DV_PRESET ioctls: VIDIOC_G_DV_PRESET, +VIDIOC_S_DV_PRESET, VIDIOC_QUERY_DV_PRESET and +VIDIOC_ENUM_DV_PRESET. Remove the related v4l2_input/output +capability flags V4L2_IN_CAP_PRESETS and V4L2_OUT_CAP_PRESETS. +Added VIDIOC_DBG_G_CHIP_INFO. + + +:revision: 3.9 / 2012-12-03 (*sa, sn*) + +Added timestamp types to v4l2_buffer. Added +V4L2_EVENT_CTRL_CH_RANGE control event changes flag. + + +:revision: 3.6 / 2012-07-02 (*hv*) + +Added VIDIOC_ENUM_FREQ_BANDS. + + +:revision: 3.5 / 2012-05-07 (*sa, sn, hv*) + +Added V4L2_CTRL_TYPE_INTEGER_MENU and V4L2 subdev selections API. +Improved the description of V4L2_CID_COLORFX control, added +V4L2_CID_COLORFX_CBCR control. Added camera controls +V4L2_CID_AUTO_EXPOSURE_BIAS, +V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE, +V4L2_CID_IMAGE_STABILIZATION, V4L2_CID_ISO_SENSITIVITY, +V4L2_CID_ISO_SENSITIVITY_AUTO, V4L2_CID_EXPOSURE_METERING, +V4L2_CID_SCENE_MODE, V4L2_CID_3A_LOCK, +V4L2_CID_AUTO_FOCUS_START, V4L2_CID_AUTO_FOCUS_STOP, +V4L2_CID_AUTO_FOCUS_STATUS and V4L2_CID_AUTO_FOCUS_RANGE. Added +VIDIOC_ENUM_DV_TIMINGS, VIDIOC_QUERY_DV_TIMINGS and +VIDIOC_DV_TIMINGS_CAP. + + +:revision: 3.4 / 2012-01-25 (*sn*) + +Added :ref:`JPEG compression control class. <jpeg-controls>` + + +:revision: 3.3 / 2012-01-11 (*hv*) + +Added device_caps field to struct v4l2_capabilities. + + +:revision: 3.2 / 2011-08-26 (*hv*) + +Added V4L2_CTRL_FLAG_VOLATILE. + + +:revision: 3.1 / 2011-06-27 (*mcc, po, hv*) + +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. + + +:revision: 2.6.39 / 2011-03-01 (*mcc, po*) + +Removed VIDIOC_*_OLD from videodev2.h header and update it to reflect +latest changes. Added the :ref:`multi-planar API <planar-apis>`. + + +:revision: 2.6.37 / 2010-08-06 (*hv*) + +Removed obsolete vtx (videotext) API. + + +:revision: 2.6.33 / 2009-12-03 (*mk*) + +Added documentation for the Digital Video timings API. + + +:revision: 2.6.32 / 2009-08-31 (*mcc*) + +Now, revisions will match the kernel version where the V4L2 API changes +will be used by the Linux Kernel. Also added Remote Controller chapter. + + +:revision: 0.29 / 2009-08-26 (*ev*) + +Added documentation for string controls and for FM Transmitter controls. + + +:revision: 0.28 / 2009-08-26 (*gl*) + +Added V4L2_CID_BAND_STOP_FILTER documentation. + + +:revision: 0.27 / 2009-08-15 (*mcc*) + +Added libv4l and Remote Controller documentation; added v4l2grab and +keytable application examples. + + +:revision: 0.26 / 2009-07-23 (*hv*) + +Finalized the RDS capture API. Added modulator and RDS encoder +capabilities. Added support for string controls. + + +:revision: 0.25 / 2009-01-18 (*hv*) + +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. + + +:revision: 0.24 / 2008-03-04 (*mhs*) + +Added pixel formats Y16 and SBGGR16, new controls and a camera controls +class. Removed VIDIOC_G/S_MPEGCOMP. + + +:revision: 0.23 / 2007-08-30 (*mhs*) + +Fixed a typo in VIDIOC_DBG_G/S_REGISTER. Clarified the byte order of +packed pixel formats. + + +:revision: 0.22 / 2007-08-29 (*mhs*) + +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. + + +:revision: 0.21 / 2006-12-19 (*mhs*) + +Fixed a link in the VIDIOC_G_EXT_CTRLS section. + + +:revision: 0.20 / 2006-11-24 (*mhs*) + +Clarified the purpose of the audioset field in struct v4l2_input and +v4l2_output. + + +:revision: 0.19 / 2006-10-19 (*mhs*) + +Documented V4L2_PIX_FMT_RGB444. + + +:revision: 0.18 / 2006-10-18 (*mhs*) + +Added the description of extended controls by Hans Verkuil. Linked +V4L2_PIX_FMT_MPEG to V4L2_CID_MPEG_STREAM_TYPE. + + +:revision: 0.17 / 2006-10-12 (*mhs*) + +Corrected V4L2_PIX_FMT_HM12 description. + + +:revision: 0.16 / 2006-10-08 (*mhs*) + +VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS are now part +of the API. + + +:revision: 0.15 / 2006-09-23 (*mhs*) + +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. + + +:revision: 0.14 / 2006-09-14 (*mr*) + +Added VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS proposal +for frame format enumeration of digital devices. + + +:revision: 0.13 / 2006-04-07 (*mhs*) + +Corrected the description of struct v4l2_window clips. New V4L2_STD\_ +and V4L2_TUNER_MODE_LANG1_LANG2 defines. + + +:revision: 0.12 / 2006-02-03 (*mhs*) + +Corrected the description of struct v4l2_captureparm and +v4l2_outputparm. + + +:revision: 0.11 / 2006-01-27 (*mhs*) + +Improved the description of struct v4l2_tuner. + + +:revision: 0.10 / 2006-01-10 (*mhs*) + +VIDIOC_G_INPUT and VIDIOC_S_PARM clarifications. + + +:revision: 0.9 / 2005-11-27 (*mhs*) + +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. + + +:revision: 0.8 / 2004-10-04 (*mhs*) + +Somehow a piece of junk slipped into the capture example, removed. + + +:revision: 0.7 / 2004-09-19 (*mhs*) + +Fixed video standard selection, control enumeration, downscaling and +aspect example. Added read and user pointer i/o to video capture +example. + + +:revision: 0.6 / 2004-08-01 (*mhs*) + +v4l2_buffer changes, added video capture example, various corrections. + + +:revision: 0.5 / 2003-11-05 (*mhs*) + +Pixel format erratum. + + +:revision: 0.4 / 2003-09-17 (*mhs*) + +Corrected source and Makefile to generate a PDF. SGML fixes. Added +latest API changes. Closed gaps in the history chapter. + + +:revision: 0.3 / 2003-02-05 (*mhs*) + +Another draft, more corrections. + + +:revision: 0.2 / 2003-01-15 (*mhs*) + +Second draft, with corrections pointed out by Gerd Knorr. + + +:revision: 0.1 / 2002-12-01 (*mhs*) + +First draft, based on documentation by Bill Dirks and discussions on the +V4L mailing list. |