1 .. Permission is granted to copy, distribute and/or modify this
2 .. document under the terms of the GNU Free Documentation License,
3 .. Version 1.1 or any later version published by the Free Software
4 .. Foundation, with no Invariant Sections, no Front-Cover Texts
5 .. and no Back-Cover Texts. A copy of the license is included at
6 .. Documentation/userspace-api/media/fdl-appendix.rst.
8 .. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
10 .. include:: <isonum.txt>
13 ############################
14 Part I - Video for Linux API
15 ############################
17 This part describes the Video for Linux API version 2 (V4L2 API) specification.
45 **********************
46 Revision and Copyright
47 **********************
49 Authors, in alphabetical order:
51 - Ailus, Sakari <sakari.ailus@iki.fi>
53 - Subdev selections API.
55 - Carvalho Chehab, Mauro <mchehab+samsung@kernel.org>
57 - Documented libv4l, designed and added v4l2grab example, Remote Controller chapter.
61 - Original author of the V4L2 API and documentation.
63 - Figa, Tomasz <tfiga@chromium.org>
65 - Documented the memory-to-memory decoder interface.
66 - Documented the memory-to-memory encoder interface.
68 - H Schimek, Michael <mschimek@gmx.at>
70 - Original author of the V4L2 API and documentation.
72 - Karicheri, Muralidharan <m-karicheri2@ti.com>
74 - Documented the Digital Video timings API.
76 - Osciak, Pawel <posciak@chromium.org>
78 - Documented the memory-to-memory decoder interface.
79 - Documented the memory-to-memory encoder interface.
81 - Osciak, Pawel <pawel@osciak.com>
83 - Designed and documented the multi-planar API.
85 - Palosaari, Antti <crope@iki.fi>
91 - Introduce HSV formats and other minor changes.
95 - Designed and documented the VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS ioctls.
97 - Walls, Andy <awalls@md.metrocast.net>
99 - Documented the fielded V4L2_MPEG_STREAM_VBI_FMT_IVTV MPEG stream embedded, sliced VBI data format in this specification.
101 - Verkuil, Hans <hverkuil@xs4all.nl>
103 - 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.
105 **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
107 Except when explicitly stated as GPL, programming examples within this
108 part can be used and distributed without restrictions.
114 :revision: 4.10 / 2016-07-15 (*rr*)
116 Introduce HSV formats.
119 :revision: 4.5 / 2015-10-29 (*rr*)
121 Extend VIDIOC_G_EXT_CTRLS;. Replace ctrl_class with a new union with
122 ctrl_class and which. Which is used to select the current value of the
123 control or the default value.
126 :revision: 4.4 / 2015-05-26 (*ap*)
128 Renamed V4L2_TUNER_ADC to V4L2_TUNER_SDR. Added
129 V4L2_CID_RF_TUNER_RF_GAIN control. Added transmitter support for
130 Software Defined Radio (SDR) Interface.
133 :revision: 4.1 / 2015-02-13 (*mcc*)
135 Fix documentation for media controller device nodes and add support for
136 DVB device nodes. Add support for Tuner sub-device.
139 :revision: 3.19 / 2014-12-05 (*hv*)
141 Rewrote Colorspace chapter, added new enum
142 :c:type:`v4l2_ycbcr_encoding` and enum
143 :c:type:`v4l2_quantization` fields to struct
144 :c:type:`v4l2_pix_format`, struct
145 :c:type:`v4l2_pix_format_mplane` and struct
146 :c:type:`v4l2_mbus_framefmt`.
149 :revision: 3.17 / 2014-08-04 (*lp, hv*)
151 Extended struct :c:type:`v4l2_pix_format`. Added
152 format flags. Added compound control types and VIDIOC_QUERY_EXT_CTRL.
155 :revision: 3.15 / 2014-02-03 (*hv, ap*)
157 Update several sections of "Common API Elements": "Opening and Closing
158 Devices" "Querying Capabilities", "Application Priority", "Video Inputs
159 and Outputs", "Audio Inputs and Outputs" "Tuners and Modulators", "Video
160 Standards" and "Digital Video (DV) Timings". Added SDR API.
163 :revision: 3.14 / 2013-11-25 (*rr*)
165 Set width and height as unsigned on v4l2_rect.
168 :revision: 3.11 / 2013-05-26 (*hv*)
170 Remove obsolete VIDIOC_DBG_G_CHIP_IDENT ioctl.
173 :revision: 3.10 / 2013-03-25 (*hv*)
175 Remove obsolete and unused DV_PRESET ioctls: VIDIOC_G_DV_PRESET,
176 VIDIOC_S_DV_PRESET, VIDIOC_QUERY_DV_PRESET and
177 VIDIOC_ENUM_DV_PRESET. Remove the related v4l2_input/output
178 capability flags V4L2_IN_CAP_PRESETS and V4L2_OUT_CAP_PRESETS.
179 Added VIDIOC_DBG_G_CHIP_INFO.
182 :revision: 3.9 / 2012-12-03 (*sa, sn*)
184 Added timestamp types to v4l2_buffer. Added
185 V4L2_EVENT_CTRL_CH_RANGE control event changes flag.
188 :revision: 3.6 / 2012-07-02 (*hv*)
190 Added VIDIOC_ENUM_FREQ_BANDS.
193 :revision: 3.5 / 2012-05-07 (*sa, sn, hv*)
195 Added V4L2_CTRL_TYPE_INTEGER_MENU and V4L2 subdev selections API.
196 Improved the description of V4L2_CID_COLORFX control, added
197 V4L2_CID_COLORFX_CBCR control. Added camera controls
198 V4L2_CID_AUTO_EXPOSURE_BIAS,
199 V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE,
200 V4L2_CID_IMAGE_STABILIZATION, V4L2_CID_ISO_SENSITIVITY,
201 V4L2_CID_ISO_SENSITIVITY_AUTO, V4L2_CID_EXPOSURE_METERING,
202 V4L2_CID_SCENE_MODE, V4L2_CID_3A_LOCK,
203 V4L2_CID_AUTO_FOCUS_START, V4L2_CID_AUTO_FOCUS_STOP,
204 V4L2_CID_AUTO_FOCUS_STATUS and V4L2_CID_AUTO_FOCUS_RANGE. Added
205 VIDIOC_ENUM_DV_TIMINGS, VIDIOC_QUERY_DV_TIMINGS and
206 VIDIOC_DV_TIMINGS_CAP.
209 :revision: 3.4 / 2012-01-25 (*sn*)
211 Added :ref:`JPEG compression control class. <jpeg-controls>`
214 :revision: 3.3 / 2012-01-11 (*hv*)
216 Added device_caps field to struct v4l2_capabilities.
219 :revision: 3.2 / 2011-08-26 (*hv*)
221 Added V4L2_CTRL_FLAG_VOLATILE.
224 :revision: 3.1 / 2011-06-27 (*mcc, po, hv*)
226 Documented that VIDIOC_QUERYCAP now returns a per-subsystem version
227 instead of a per-driver one. Standardize an error code for invalid
228 ioctl. Added V4L2_CTRL_TYPE_BITMASK.
231 :revision: 2.6.39 / 2011-03-01 (*mcc, po*)
233 Removed VIDIOC_*_OLD from videodev2.h header and update it to reflect
234 latest changes. Added the :ref:`multi-planar API <planar-apis>`.
237 :revision: 2.6.37 / 2010-08-06 (*hv*)
239 Removed obsolete vtx (videotext) API.
242 :revision: 2.6.33 / 2009-12-03 (*mk*)
244 Added documentation for the Digital Video timings API.
247 :revision: 2.6.32 / 2009-08-31 (*mcc*)
249 Now, revisions will match the kernel version where the V4L2 API changes
250 will be used by the Linux Kernel. Also added Remote Controller chapter.
253 :revision: 0.29 / 2009-08-26 (*ev*)
255 Added documentation for string controls and for FM Transmitter controls.
258 :revision: 0.28 / 2009-08-26 (*gl*)
260 Added V4L2_CID_BAND_STOP_FILTER documentation.
263 :revision: 0.27 / 2009-08-15 (*mcc*)
265 Added libv4l and Remote Controller documentation; added v4l2grab and
266 keytable application examples.
269 :revision: 0.26 / 2009-07-23 (*hv*)
271 Finalized the RDS capture API. Added modulator and RDS encoder
272 capabilities. Added support for string controls.
275 :revision: 0.25 / 2009-01-18 (*hv*)
277 Added pixel formats VYUY, NV16 and NV61, and changed the debug ioctls
278 VIDIOC_DBG_G/S_REGISTER and VIDIOC_DBG_G_CHIP_IDENT. Added camera
279 controls V4L2_CID_ZOOM_ABSOLUTE, V4L2_CID_ZOOM_RELATIVE,
280 V4L2_CID_ZOOM_CONTINUOUS and V4L2_CID_PRIVACY.
283 :revision: 0.24 / 2008-03-04 (*mhs*)
285 Added pixel formats Y16 and SBGGR16, new controls and a camera controls
286 class. Removed VIDIOC_G/S_MPEGCOMP.
289 :revision: 0.23 / 2007-08-30 (*mhs*)
291 Fixed a typo in VIDIOC_DBG_G/S_REGISTER. Clarified the byte order of
292 packed pixel formats.
295 :revision: 0.22 / 2007-08-29 (*mhs*)
297 Added the Video Output Overlay interface, new MPEG controls,
298 V4L2_FIELD_INTERLACED_TB and V4L2_FIELD_INTERLACED_BT,
299 VIDIOC_DBG_G/S_REGISTER, VIDIOC\_(TRY\_)ENCODER_CMD,
300 VIDIOC_G_CHIP_IDENT, VIDIOC_G_ENC_INDEX, new pixel formats.
301 Clarifications in the cropping chapter, about RGB pixel formats, the
302 mmap(), poll(), select(), read() and write() functions. Typographical
306 :revision: 0.21 / 2006-12-19 (*mhs*)
308 Fixed a link in the VIDIOC_G_EXT_CTRLS section.
311 :revision: 0.20 / 2006-11-24 (*mhs*)
313 Clarified the purpose of the audioset field in struct v4l2_input and
317 :revision: 0.19 / 2006-10-19 (*mhs*)
319 Documented V4L2_PIX_FMT_RGB444.
322 :revision: 0.18 / 2006-10-18 (*mhs*)
324 Added the description of extended controls by Hans Verkuil. Linked
325 V4L2_PIX_FMT_MPEG to V4L2_CID_MPEG_STREAM_TYPE.
328 :revision: 0.17 / 2006-10-12 (*mhs*)
330 Corrected V4L2_PIX_FMT_HM12 description.
333 :revision: 0.16 / 2006-10-08 (*mhs*)
335 VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS are now part
339 :revision: 0.15 / 2006-09-23 (*mhs*)
341 Cleaned up the bibliography, added BT.653 and BT.1119.
342 capture.c/start_capturing() for user pointer I/O did not initialize the
343 buffer index. Documented the V4L MPEG and MJPEG VID_TYPEs and
344 V4L2_PIX_FMT_SBGGR8. Updated the list of reserved pixel formats. See
345 the history chapter for API changes.
348 :revision: 0.14 / 2006-09-14 (*mr*)
350 Added VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS proposal
351 for frame format enumeration of digital devices.
354 :revision: 0.13 / 2006-04-07 (*mhs*)
356 Corrected the description of struct v4l2_window clips. New V4L2_STD\_
357 and V4L2_TUNER_MODE_LANG1_LANG2 defines.
360 :revision: 0.12 / 2006-02-03 (*mhs*)
362 Corrected the description of struct v4l2_captureparm and
366 :revision: 0.11 / 2006-01-27 (*mhs*)
368 Improved the description of struct v4l2_tuner.
371 :revision: 0.10 / 2006-01-10 (*mhs*)
373 VIDIOC_G_INPUT and VIDIOC_S_PARM clarifications.
376 :revision: 0.9 / 2005-11-27 (*mhs*)
378 Improved the 525 line numbering diagram. Hans Verkuil and I rewrote the
379 sliced VBI section. He also contributed a VIDIOC_LOG_STATUS page.
380 Fixed VIDIOC_S_STD call in the video standard selection example.
384 :revision: 0.8 / 2004-10-04 (*mhs*)
386 Somehow a piece of junk slipped into the capture example, removed.
389 :revision: 0.7 / 2004-09-19 (*mhs*)
391 Fixed video standard selection, control enumeration, downscaling and
392 aspect example. Added read and user pointer i/o to video capture
396 :revision: 0.6 / 2004-08-01 (*mhs*)
398 v4l2_buffer changes, added video capture example, various corrections.
401 :revision: 0.5 / 2003-11-05 (*mhs*)
403 Pixel format erratum.
406 :revision: 0.4 / 2003-09-17 (*mhs*)
408 Corrected source and Makefile to generate a PDF. SGML fixes. Added
409 latest API changes. Closed gaps in the history chapter.
412 :revision: 0.3 / 2003-02-05 (*mhs*)
414 Another draft, more corrections.
417 :revision: 0.2 / 2003-01-15 (*mhs*)
419 Second draft, with corrections pointed out by Gerd Knorr.
422 :revision: 0.1 / 2002-12-01 (*mhs*)
424 First draft, based on documentation by Bill Dirks and discussions on the