1 .. SPDX-License-Identifier: GFDL-1.1-no-invari 1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2 2 3 .. _camera-controls: 3 .. _camera-controls: 4 4 5 ************************ 5 ************************ 6 Camera Control Reference 6 Camera Control Reference 7 ************************ 7 ************************ 8 8 9 The Camera class includes controls for mechani 9 The Camera class includes controls for mechanical (or equivalent 10 digital) features of a device such as controll 10 digital) features of a device such as controllable lenses or sensors. 11 11 12 12 13 .. _camera-control-id: 13 .. _camera-control-id: 14 14 15 Camera Control IDs 15 Camera Control IDs 16 ================== 16 ================== 17 17 18 ``V4L2_CID_CAMERA_CLASS (class)`` 18 ``V4L2_CID_CAMERA_CLASS (class)`` 19 The Camera class descriptor. Calling 19 The Camera class descriptor. Calling 20 :ref:`VIDIOC_QUERYCTRL` for this control w 20 :ref:`VIDIOC_QUERYCTRL` for this control will 21 return a description of this control class 21 return a description of this control class. 22 22 23 .. _v4l2-exposure-auto-type: 23 .. _v4l2-exposure-auto-type: 24 24 25 ``V4L2_CID_EXPOSURE_AUTO`` 25 ``V4L2_CID_EXPOSURE_AUTO`` 26 (enum) 26 (enum) 27 27 28 enum v4l2_exposure_auto_type - 28 enum v4l2_exposure_auto_type - 29 Enables automatic adjustments of the expos 29 Enables automatic adjustments of the exposure time and/or iris 30 aperture. The effect of manual changes of 30 aperture. The effect of manual changes of the exposure time or iris 31 aperture while these features are enabled 31 aperture while these features are enabled is undefined, drivers 32 should ignore such requests. Possible valu 32 should ignore such requests. Possible values are: 33 33 34 34 35 .. tabularcolumns:: |p{7.1cm}|p{10.4cm}| 35 .. tabularcolumns:: |p{7.1cm}|p{10.4cm}| 36 36 37 .. flat-table:: 37 .. flat-table:: 38 :header-rows: 0 38 :header-rows: 0 39 :stub-columns: 0 39 :stub-columns: 0 40 40 41 * - ``V4L2_EXPOSURE_AUTO`` 41 * - ``V4L2_EXPOSURE_AUTO`` 42 - Automatic exposure time, automatic iri 42 - Automatic exposure time, automatic iris aperture. 43 * - ``V4L2_EXPOSURE_MANUAL`` 43 * - ``V4L2_EXPOSURE_MANUAL`` 44 - Manual exposure time, manual iris. 44 - Manual exposure time, manual iris. 45 * - ``V4L2_EXPOSURE_SHUTTER_PRIORITY`` 45 * - ``V4L2_EXPOSURE_SHUTTER_PRIORITY`` 46 - Manual exposure time, auto iris. 46 - Manual exposure time, auto iris. 47 * - ``V4L2_EXPOSURE_APERTURE_PRIORITY`` 47 * - ``V4L2_EXPOSURE_APERTURE_PRIORITY`` 48 - Auto exposure time, manual iris. 48 - Auto exposure time, manual iris. 49 49 50 50 51 51 52 ``V4L2_CID_EXPOSURE_ABSOLUTE (integer)`` 52 ``V4L2_CID_EXPOSURE_ABSOLUTE (integer)`` 53 Determines the exposure time of the camera 53 Determines the exposure time of the camera sensor. The exposure time 54 is limited by the frame interval. Drivers 54 is limited by the frame interval. Drivers should interpret the 55 values as 100 µs units, where the value 1 55 values as 100 µs units, where the value 1 stands for 1/10000th of a 56 second, 10000 for 1 second and 100000 for 56 second, 10000 for 1 second and 100000 for 10 seconds. 57 57 58 ``V4L2_CID_EXPOSURE_AUTO_PRIORITY (boolean)`` 58 ``V4L2_CID_EXPOSURE_AUTO_PRIORITY (boolean)`` 59 When ``V4L2_CID_EXPOSURE_AUTO`` is set to 59 When ``V4L2_CID_EXPOSURE_AUTO`` is set to ``AUTO`` or 60 ``APERTURE_PRIORITY``, this control determ 60 ``APERTURE_PRIORITY``, this control determines if the device may 61 dynamically vary the frame rate. By defaul 61 dynamically vary the frame rate. By default this feature is disabled 62 (0) and the frame rate must remain constan 62 (0) and the frame rate must remain constant. 63 63 64 ``V4L2_CID_AUTO_EXPOSURE_BIAS (integer menu)`` 64 ``V4L2_CID_AUTO_EXPOSURE_BIAS (integer menu)`` 65 Determines the automatic exposure compensa 65 Determines the automatic exposure compensation, it is effective only 66 when ``V4L2_CID_EXPOSURE_AUTO`` control is 66 when ``V4L2_CID_EXPOSURE_AUTO`` control is set to ``AUTO``, 67 ``SHUTTER_PRIORITY`` or ``APERTURE_PRIORIT 67 ``SHUTTER_PRIORITY`` or ``APERTURE_PRIORITY``. It is expressed in 68 terms of EV, drivers should interpret the 68 terms of EV, drivers should interpret the values as 0.001 EV units, 69 where the value 1000 stands for +1 EV. 69 where the value 1000 stands for +1 EV. 70 70 71 Increasing the exposure compensation value 71 Increasing the exposure compensation value is equivalent to 72 decreasing the exposure value (EV) and wil 72 decreasing the exposure value (EV) and will increase the amount of 73 light at the image sensor. The camera perf 73 light at the image sensor. The camera performs the exposure 74 compensation by adjusting absolute exposur 74 compensation by adjusting absolute exposure time and/or aperture. 75 75 76 .. _v4l2-exposure-metering: 76 .. _v4l2-exposure-metering: 77 77 78 ``V4L2_CID_EXPOSURE_METERING`` 78 ``V4L2_CID_EXPOSURE_METERING`` 79 (enum) 79 (enum) 80 80 81 enum v4l2_exposure_metering - 81 enum v4l2_exposure_metering - 82 Determines how the camera measures the amo 82 Determines how the camera measures the amount of light available for 83 the frame exposure. Possible values are: 83 the frame exposure. Possible values are: 84 84 85 .. tabularcolumns:: |p{8.7cm}|p{8.7cm}| 85 .. tabularcolumns:: |p{8.7cm}|p{8.7cm}| 86 86 87 .. flat-table:: 87 .. flat-table:: 88 :header-rows: 0 88 :header-rows: 0 89 :stub-columns: 0 89 :stub-columns: 0 90 90 91 * - ``V4L2_EXPOSURE_METERING_AVERAGE`` 91 * - ``V4L2_EXPOSURE_METERING_AVERAGE`` 92 - Use the light information coming from 92 - Use the light information coming from the entire frame and average 93 giving no weighting to any particular 93 giving no weighting to any particular portion of the metered area. 94 * - ``V4L2_EXPOSURE_METERING_CENTER_WEIGHT 94 * - ``V4L2_EXPOSURE_METERING_CENTER_WEIGHTED`` 95 - Average the light information coming f 95 - Average the light information coming from the entire frame giving 96 priority to the center of the metered 96 priority to the center of the metered area. 97 * - ``V4L2_EXPOSURE_METERING_SPOT`` 97 * - ``V4L2_EXPOSURE_METERING_SPOT`` 98 - Measure only very small area at the ce 98 - Measure only very small area at the center of the frame. 99 * - ``V4L2_EXPOSURE_METERING_MATRIX`` 99 * - ``V4L2_EXPOSURE_METERING_MATRIX`` 100 - A multi-zone metering. The light inten 100 - A multi-zone metering. The light intensity is measured in several 101 points of the frame and the results ar 101 points of the frame and the results are combined. The algorithm of 102 the zones selection and their signific 102 the zones selection and their significance in calculating the 103 final value is device dependent. 103 final value is device dependent. 104 104 105 105 106 106 107 ``V4L2_CID_PAN_RELATIVE (integer)`` 107 ``V4L2_CID_PAN_RELATIVE (integer)`` 108 This control turns the camera horizontally 108 This control turns the camera horizontally by the specified amount. 109 The unit is undefined. A positive value mo 109 The unit is undefined. A positive value moves the camera to the 110 right (clockwise when viewed from above), 110 right (clockwise when viewed from above), a negative value to the 111 left. A value of zero does not cause motio 111 left. A value of zero does not cause motion. This is a write-only 112 control. 112 control. 113 113 114 ``V4L2_CID_TILT_RELATIVE (integer)`` 114 ``V4L2_CID_TILT_RELATIVE (integer)`` 115 This control turns the camera vertically b 115 This control turns the camera vertically by the specified amount. 116 The unit is undefined. A positive value mo 116 The unit is undefined. A positive value moves the camera up, a 117 negative value down. A value of zero does 117 negative value down. A value of zero does not cause motion. This is 118 a write-only control. 118 a write-only control. 119 119 120 ``V4L2_CID_PAN_RESET (button)`` 120 ``V4L2_CID_PAN_RESET (button)`` 121 When this control is set, the camera moves 121 When this control is set, the camera moves horizontally to the 122 default position. 122 default position. 123 123 124 ``V4L2_CID_TILT_RESET (button)`` 124 ``V4L2_CID_TILT_RESET (button)`` 125 When this control is set, the camera moves 125 When this control is set, the camera moves vertically to the default 126 position. 126 position. 127 127 128 ``V4L2_CID_PAN_ABSOLUTE (integer)`` 128 ``V4L2_CID_PAN_ABSOLUTE (integer)`` 129 This control turns the camera horizontally 129 This control turns the camera horizontally to the specified 130 position. Positive values move the camera 130 position. Positive values move the camera to the right (clockwise 131 when viewed from above), negative values t 131 when viewed from above), negative values to the left. Drivers should 132 interpret the values as arc seconds, with 132 interpret the values as arc seconds, with valid values between -180 133 * 3600 and +180 * 3600 inclusive. 133 * 3600 and +180 * 3600 inclusive. 134 134 135 ``V4L2_CID_TILT_ABSOLUTE (integer)`` 135 ``V4L2_CID_TILT_ABSOLUTE (integer)`` 136 This control turns the camera vertically t 136 This control turns the camera vertically to the specified position. 137 Positive values move the camera up, negati 137 Positive values move the camera up, negative values down. Drivers 138 should interpret the values as arc seconds 138 should interpret the values as arc seconds, with valid values 139 between -180 * 3600 and +180 * 3600 inclus 139 between -180 * 3600 and +180 * 3600 inclusive. 140 140 141 ``V4L2_CID_FOCUS_ABSOLUTE (integer)`` 141 ``V4L2_CID_FOCUS_ABSOLUTE (integer)`` 142 This control sets the focal point of the c 142 This control sets the focal point of the camera to the specified 143 position. The unit is undefined. Positive 143 position. The unit is undefined. Positive values set the focus 144 closer to the camera, negative values towa 144 closer to the camera, negative values towards infinity. 145 145 146 ``V4L2_CID_FOCUS_RELATIVE (integer)`` 146 ``V4L2_CID_FOCUS_RELATIVE (integer)`` 147 This control moves the focal point of the 147 This control moves the focal point of the camera by the specified 148 amount. The unit is undefined. Positive va 148 amount. The unit is undefined. Positive values move the focus closer 149 to the camera, negative values towards inf 149 to the camera, negative values towards infinity. This is a 150 write-only control. 150 write-only control. 151 151 152 ``V4L2_CID_FOCUS_AUTO (boolean)`` 152 ``V4L2_CID_FOCUS_AUTO (boolean)`` 153 Enables continuous automatic focus adjustm 153 Enables continuous automatic focus adjustments. The effect of manual 154 focus adjustments while this feature is en 154 focus adjustments while this feature is enabled is undefined, 155 drivers should ignore such requests. 155 drivers should ignore such requests. 156 156 157 ``V4L2_CID_AUTO_FOCUS_START (button)`` 157 ``V4L2_CID_AUTO_FOCUS_START (button)`` 158 Starts single auto focus process. The effe 158 Starts single auto focus process. The effect of setting this control 159 when ``V4L2_CID_FOCUS_AUTO`` is set to ``T 159 when ``V4L2_CID_FOCUS_AUTO`` is set to ``TRUE`` (1) is undefined, 160 drivers should ignore such requests. 160 drivers should ignore such requests. 161 161 162 ``V4L2_CID_AUTO_FOCUS_STOP (button)`` 162 ``V4L2_CID_AUTO_FOCUS_STOP (button)`` 163 Aborts automatic focusing started with ``V 163 Aborts automatic focusing started with ``V4L2_CID_AUTO_FOCUS_START`` 164 control. It is effective only when the con 164 control. It is effective only when the continuous autofocus is 165 disabled, that is when ``V4L2_CID_FOCUS_AU 165 disabled, that is when ``V4L2_CID_FOCUS_AUTO`` control is set to 166 ``FALSE`` (0). 166 ``FALSE`` (0). 167 167 168 .. _v4l2-auto-focus-status: 168 .. _v4l2-auto-focus-status: 169 169 170 ``V4L2_CID_AUTO_FOCUS_STATUS (bitmask)`` 170 ``V4L2_CID_AUTO_FOCUS_STATUS (bitmask)`` 171 The automatic focus status. This is a read 171 The automatic focus status. This is a read-only control. 172 172 173 Setting ``V4L2_LOCK_FOCUS`` lock bit of th 173 Setting ``V4L2_LOCK_FOCUS`` lock bit of the ``V4L2_CID_3A_LOCK`` 174 control may stop updates of the ``V4L2_CID 174 control may stop updates of the ``V4L2_CID_AUTO_FOCUS_STATUS`` 175 control value. 175 control value. 176 176 177 .. tabularcolumns:: |p{6.8cm}|p{10.7cm}| 177 .. tabularcolumns:: |p{6.8cm}|p{10.7cm}| 178 178 179 .. flat-table:: 179 .. flat-table:: 180 :header-rows: 0 180 :header-rows: 0 181 :stub-columns: 0 181 :stub-columns: 0 182 182 183 * - ``V4L2_AUTO_FOCUS_STATUS_IDLE`` 183 * - ``V4L2_AUTO_FOCUS_STATUS_IDLE`` 184 - Automatic focus is not active. 184 - Automatic focus is not active. 185 * - ``V4L2_AUTO_FOCUS_STATUS_BUSY`` 185 * - ``V4L2_AUTO_FOCUS_STATUS_BUSY`` 186 - Automatic focusing is in progress. 186 - Automatic focusing is in progress. 187 * - ``V4L2_AUTO_FOCUS_STATUS_REACHED`` 187 * - ``V4L2_AUTO_FOCUS_STATUS_REACHED`` 188 - Focus has been reached. 188 - Focus has been reached. 189 * - ``V4L2_AUTO_FOCUS_STATUS_FAILED`` 189 * - ``V4L2_AUTO_FOCUS_STATUS_FAILED`` 190 - Automatic focus has failed, the driver 190 - Automatic focus has failed, the driver will not transition from 191 this state until another action is per 191 this state until another action is performed by an application. 192 192 193 193 194 194 195 .. _v4l2-auto-focus-range: 195 .. _v4l2-auto-focus-range: 196 196 197 ``V4L2_CID_AUTO_FOCUS_RANGE`` 197 ``V4L2_CID_AUTO_FOCUS_RANGE`` 198 (enum) 198 (enum) 199 199 200 enum v4l2_auto_focus_range - 200 enum v4l2_auto_focus_range - 201 Determines auto focus distance range for w 201 Determines auto focus distance range for which lens may be adjusted. 202 202 203 .. tabularcolumns:: |p{6.9cm}|p{10.6cm}| 203 .. tabularcolumns:: |p{6.9cm}|p{10.6cm}| 204 204 205 .. flat-table:: 205 .. flat-table:: 206 :header-rows: 0 206 :header-rows: 0 207 :stub-columns: 0 207 :stub-columns: 0 208 208 209 * - ``V4L2_AUTO_FOCUS_RANGE_AUTO`` 209 * - ``V4L2_AUTO_FOCUS_RANGE_AUTO`` 210 - The camera automatically selects the f 210 - The camera automatically selects the focus range. 211 * - ``V4L2_AUTO_FOCUS_RANGE_NORMAL`` 211 * - ``V4L2_AUTO_FOCUS_RANGE_NORMAL`` 212 - Normal distance range, limited for bes 212 - Normal distance range, limited for best automatic focus 213 performance. 213 performance. 214 * - ``V4L2_AUTO_FOCUS_RANGE_MACRO`` 214 * - ``V4L2_AUTO_FOCUS_RANGE_MACRO`` 215 - Macro (close-up) auto focus. The camer 215 - Macro (close-up) auto focus. The camera will use its minimum 216 possible distance for auto focus. 216 possible distance for auto focus. 217 * - ``V4L2_AUTO_FOCUS_RANGE_INFINITY`` 217 * - ``V4L2_AUTO_FOCUS_RANGE_INFINITY`` 218 - The lens is set to focus on an object 218 - The lens is set to focus on an object at infinite distance. 219 219 220 220 221 221 222 ``V4L2_CID_ZOOM_ABSOLUTE (integer)`` 222 ``V4L2_CID_ZOOM_ABSOLUTE (integer)`` 223 Specify the objective lens focal length as 223 Specify the objective lens focal length as an absolute value. The 224 zoom unit is driver-specific and its value 224 zoom unit is driver-specific and its value should be a positive 225 integer. 225 integer. 226 226 227 ``V4L2_CID_ZOOM_RELATIVE (integer)`` 227 ``V4L2_CID_ZOOM_RELATIVE (integer)`` 228 Specify the objective lens focal length re 228 Specify the objective lens focal length relatively to the current 229 value. Positive values move the zoom lens 229 value. Positive values move the zoom lens group towards the 230 telephoto direction, negative values towar 230 telephoto direction, negative values towards the wide-angle 231 direction. The zoom unit is driver-specifi 231 direction. The zoom unit is driver-specific. This is a write-only 232 control. 232 control. 233 233 234 ``V4L2_CID_ZOOM_CONTINUOUS (integer)`` 234 ``V4L2_CID_ZOOM_CONTINUOUS (integer)`` 235 Move the objective lens group at the speci 235 Move the objective lens group at the specified speed until it 236 reaches physical device limits or until an 236 reaches physical device limits or until an explicit request to stop 237 the movement. A positive value moves the z 237 the movement. A positive value moves the zoom lens group towards the 238 telephoto direction. A value of zero stops 238 telephoto direction. A value of zero stops the zoom lens group 239 movement. A negative value moves the zoom 239 movement. A negative value moves the zoom lens group towards the 240 wide-angle direction. The zoom speed unit 240 wide-angle direction. The zoom speed unit is driver-specific. 241 241 242 ``V4L2_CID_IRIS_ABSOLUTE (integer)`` 242 ``V4L2_CID_IRIS_ABSOLUTE (integer)`` 243 This control sets the camera's aperture to 243 This control sets the camera's aperture to the specified value. The 244 unit is undefined. Larger values open the 244 unit is undefined. Larger values open the iris wider, smaller values 245 close it. 245 close it. 246 246 247 ``V4L2_CID_IRIS_RELATIVE (integer)`` 247 ``V4L2_CID_IRIS_RELATIVE (integer)`` 248 This control modifies the camera's apertur 248 This control modifies the camera's aperture by the specified amount. 249 The unit is undefined. Positive values ope 249 The unit is undefined. Positive values open the iris one step 250 further, negative values close it one step 250 further, negative values close it one step further. This is a 251 write-only control. 251 write-only control. 252 252 253 ``V4L2_CID_PRIVACY (boolean)`` 253 ``V4L2_CID_PRIVACY (boolean)`` 254 Prevent video from being acquired by the c 254 Prevent video from being acquired by the camera. When this control 255 is set to ``TRUE`` (1), no image can be ca 255 is set to ``TRUE`` (1), no image can be captured by the camera. 256 Common means to enforce privacy are mechan 256 Common means to enforce privacy are mechanical obturation of the 257 sensor and firmware image processing, but 257 sensor and firmware image processing, but the device is not 258 restricted to these methods. Devices that 258 restricted to these methods. Devices that implement the privacy 259 control must support read access and may s 259 control must support read access and may support write access. 260 260 261 ``V4L2_CID_BAND_STOP_FILTER (integer)`` 261 ``V4L2_CID_BAND_STOP_FILTER (integer)`` 262 Switch the band-stop filter of a camera se 262 Switch the band-stop filter of a camera sensor on or off, or specify 263 its strength. Such band-stop filters can b 263 its strength. Such band-stop filters can be used, for example, to 264 filter out the fluorescent light component 264 filter out the fluorescent light component. 265 265 266 .. _v4l2-auto-n-preset-white-balance: 266 .. _v4l2-auto-n-preset-white-balance: 267 267 268 ``V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE`` 268 ``V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE`` 269 (enum) 269 (enum) 270 270 271 enum v4l2_auto_n_preset_white_balance - 271 enum v4l2_auto_n_preset_white_balance - 272 Sets white balance to automatic, manual or 272 Sets white balance to automatic, manual or a preset. The presets 273 determine color temperature of the light a 273 determine color temperature of the light as a hint to the camera for 274 white balance adjustments resulting in mos 274 white balance adjustments resulting in most accurate color 275 representation. The following white balanc 275 representation. The following white balance presets are listed in 276 order of increasing color temperature. 276 order of increasing color temperature. 277 277 278 .. tabularcolumns:: |p{7.4cm}|p{10.1cm}| 278 .. tabularcolumns:: |p{7.4cm}|p{10.1cm}| 279 279 280 .. flat-table:: 280 .. flat-table:: 281 :header-rows: 0 281 :header-rows: 0 282 :stub-columns: 0 282 :stub-columns: 0 283 283 284 * - ``V4L2_WHITE_BALANCE_MANUAL`` 284 * - ``V4L2_WHITE_BALANCE_MANUAL`` 285 - Manual white balance. 285 - Manual white balance. 286 * - ``V4L2_WHITE_BALANCE_AUTO`` 286 * - ``V4L2_WHITE_BALANCE_AUTO`` 287 - Automatic white balance adjustments. 287 - Automatic white balance adjustments. 288 * - ``V4L2_WHITE_BALANCE_INCANDESCENT`` 288 * - ``V4L2_WHITE_BALANCE_INCANDESCENT`` 289 - White balance setting for incandescent 289 - White balance setting for incandescent (tungsten) lighting. It 290 generally cools down the colors and co 290 generally cools down the colors and corresponds approximately to 291 2500...3500 K color temperature range. 291 2500...3500 K color temperature range. 292 * - ``V4L2_WHITE_BALANCE_FLUORESCENT`` 292 * - ``V4L2_WHITE_BALANCE_FLUORESCENT`` 293 - White balance preset for fluorescent l 293 - White balance preset for fluorescent lighting. It corresponds 294 approximately to 4000...5000 K color t 294 approximately to 4000...5000 K color temperature. 295 * - ``V4L2_WHITE_BALANCE_FLUORESCENT_H`` 295 * - ``V4L2_WHITE_BALANCE_FLUORESCENT_H`` 296 - With this setting the camera will comp 296 - With this setting the camera will compensate for fluorescent H 297 lighting. 297 lighting. 298 * - ``V4L2_WHITE_BALANCE_HORIZON`` 298 * - ``V4L2_WHITE_BALANCE_HORIZON`` 299 - White balance setting for horizon dayl 299 - White balance setting for horizon daylight. It corresponds 300 approximately to 5000 K color temperat 300 approximately to 5000 K color temperature. 301 * - ``V4L2_WHITE_BALANCE_DAYLIGHT`` 301 * - ``V4L2_WHITE_BALANCE_DAYLIGHT`` 302 - White balance preset for daylight (wit 302 - White balance preset for daylight (with clear sky). It corresponds 303 approximately to 5000...6500 K color t 303 approximately to 5000...6500 K color temperature. 304 * - ``V4L2_WHITE_BALANCE_FLASH`` 304 * - ``V4L2_WHITE_BALANCE_FLASH`` 305 - With this setting the camera will comp 305 - With this setting the camera will compensate for the flash light. 306 It slightly warms up the colors and co 306 It slightly warms up the colors and corresponds roughly to 307 5000...5500 K color temperature. 307 5000...5500 K color temperature. 308 * - ``V4L2_WHITE_BALANCE_CLOUDY`` 308 * - ``V4L2_WHITE_BALANCE_CLOUDY`` 309 - White balance preset for moderately ov 309 - White balance preset for moderately overcast sky. This option 310 corresponds approximately to 6500...80 310 corresponds approximately to 6500...8000 K color temperature 311 range. 311 range. 312 * - ``V4L2_WHITE_BALANCE_SHADE`` 312 * - ``V4L2_WHITE_BALANCE_SHADE`` 313 - White balance preset for shade or heav 313 - White balance preset for shade or heavily overcast sky. It 314 corresponds approximately to 9000...10 314 corresponds approximately to 9000...10000 K color temperature. 315 315 316 316 317 317 318 .. _v4l2-wide-dynamic-range: 318 .. _v4l2-wide-dynamic-range: 319 319 320 ``V4L2_CID_WIDE_DYNAMIC_RANGE (boolean)`` 320 ``V4L2_CID_WIDE_DYNAMIC_RANGE (boolean)`` 321 Enables or disables the camera's wide dyna 321 Enables or disables the camera's wide dynamic range feature. This 322 feature allows to obtain clear images in s 322 feature allows to obtain clear images in situations where intensity 323 of the illumination varies significantly t 323 of the illumination varies significantly throughout the scene, i.e. 324 there are simultaneously very dark and ver 324 there are simultaneously very dark and very bright areas. It is most 325 commonly realized in cameras by combining 325 commonly realized in cameras by combining two subsequent frames with 326 different exposure times. [#f1]_ 326 different exposure times. [#f1]_ 327 327 328 .. _v4l2-image-stabilization: 328 .. _v4l2-image-stabilization: 329 329 330 ``V4L2_CID_IMAGE_STABILIZATION (boolean)`` 330 ``V4L2_CID_IMAGE_STABILIZATION (boolean)`` 331 Enables or disables image stabilization. 331 Enables or disables image stabilization. 332 332 333 ``V4L2_CID_ISO_SENSITIVITY (integer menu)`` 333 ``V4L2_CID_ISO_SENSITIVITY (integer menu)`` 334 Determines ISO equivalent of an image sens 334 Determines ISO equivalent of an image sensor indicating the sensor's 335 sensitivity to light. The numbers are expr 335 sensitivity to light. The numbers are expressed in arithmetic scale, 336 as per :ref:`iso12232` standard, where dou 336 as per :ref:`iso12232` standard, where doubling the sensor 337 sensitivity is represented by doubling the 337 sensitivity is represented by doubling the numerical ISO value. 338 Applications should interpret the values a 338 Applications should interpret the values as standard ISO values 339 multiplied by 1000, e.g. control value 800 339 multiplied by 1000, e.g. control value 800 stands for ISO 0.8. 340 Drivers will usually support only a subset 340 Drivers will usually support only a subset of standard ISO values. 341 The effect of setting this control while t 341 The effect of setting this control while the 342 ``V4L2_CID_ISO_SENSITIVITY_AUTO`` control 342 ``V4L2_CID_ISO_SENSITIVITY_AUTO`` control is set to a value other 343 than ``V4L2_CID_ISO_SENSITIVITY_MANUAL`` i 343 than ``V4L2_CID_ISO_SENSITIVITY_MANUAL`` is undefined, drivers 344 should ignore such requests. 344 should ignore such requests. 345 345 346 .. _v4l2-iso-sensitivity-auto-type: 346 .. _v4l2-iso-sensitivity-auto-type: 347 347 348 ``V4L2_CID_ISO_SENSITIVITY_AUTO`` 348 ``V4L2_CID_ISO_SENSITIVITY_AUTO`` 349 (enum) 349 (enum) 350 350 351 enum v4l2_iso_sensitivity_type - 351 enum v4l2_iso_sensitivity_type - 352 Enables or disables automatic ISO sensitiv 352 Enables or disables automatic ISO sensitivity adjustments. 353 353 354 354 355 355 356 .. flat-table:: 356 .. flat-table:: 357 :header-rows: 0 357 :header-rows: 0 358 :stub-columns: 0 358 :stub-columns: 0 359 359 360 * - ``V4L2_CID_ISO_SENSITIVITY_MANUAL`` 360 * - ``V4L2_CID_ISO_SENSITIVITY_MANUAL`` 361 - Manual ISO sensitivity. 361 - Manual ISO sensitivity. 362 * - ``V4L2_CID_ISO_SENSITIVITY_AUTO`` 362 * - ``V4L2_CID_ISO_SENSITIVITY_AUTO`` 363 - Automatic ISO sensitivity adjustments. 363 - Automatic ISO sensitivity adjustments. 364 364 365 365 366 366 367 .. _v4l2-scene-mode: 367 .. _v4l2-scene-mode: 368 368 369 ``V4L2_CID_SCENE_MODE`` 369 ``V4L2_CID_SCENE_MODE`` 370 (enum) 370 (enum) 371 371 372 enum v4l2_scene_mode - 372 enum v4l2_scene_mode - 373 This control allows to select scene progra 373 This control allows to select scene programs as the camera automatic 374 modes optimized for common shooting scenes 374 modes optimized for common shooting scenes. Within these modes the 375 camera determines best exposure, aperture, 375 camera determines best exposure, aperture, focusing, light metering, 376 white balance and equivalent sensitivity. 376 white balance and equivalent sensitivity. The controls of those 377 parameters are influenced by the scene mod 377 parameters are influenced by the scene mode control. An exact 378 behavior in each mode is subject to the ca 378 behavior in each mode is subject to the camera specification. 379 379 380 When the scene mode feature is not used, t 380 When the scene mode feature is not used, this control should be set 381 to ``V4L2_SCENE_MODE_NONE`` to make sure t 381 to ``V4L2_SCENE_MODE_NONE`` to make sure the other possibly related 382 controls are accessible. The following sce 382 controls are accessible. The following scene programs are defined: 383 383 384 .. raw:: latex 384 .. raw:: latex 385 385 386 \small 386 \small 387 387 388 .. tabularcolumns:: |p{5.9cm}|p{11.6cm}| 388 .. tabularcolumns:: |p{5.9cm}|p{11.6cm}| 389 389 390 .. cssclass:: longtable 390 .. cssclass:: longtable 391 391 392 .. flat-table:: 392 .. flat-table:: 393 :header-rows: 0 393 :header-rows: 0 394 :stub-columns: 0 394 :stub-columns: 0 395 395 396 * - ``V4L2_SCENE_MODE_NONE`` 396 * - ``V4L2_SCENE_MODE_NONE`` 397 - The scene mode feature is disabled. 397 - The scene mode feature is disabled. 398 * - ``V4L2_SCENE_MODE_BACKLIGHT`` 398 * - ``V4L2_SCENE_MODE_BACKLIGHT`` 399 - Backlight. Compensates for dark shadow 399 - Backlight. Compensates for dark shadows when light is coming from 400 behind a subject, also by automaticall 400 behind a subject, also by automatically turning on the flash. 401 * - ``V4L2_SCENE_MODE_BEACH_SNOW`` 401 * - ``V4L2_SCENE_MODE_BEACH_SNOW`` 402 - Beach and snow. This mode compensates 402 - Beach and snow. This mode compensates for all-white or bright 403 scenes, which tend to look gray and lo 403 scenes, which tend to look gray and low contrast, when camera's 404 automatic exposure is based on an aver 404 automatic exposure is based on an average scene brightness. To 405 compensate, this mode automatically sl 405 compensate, this mode automatically slightly overexposes the 406 frames. The white balance may also be 406 frames. The white balance may also be adjusted to compensate for 407 the fact that reflected snow looks blu 407 the fact that reflected snow looks bluish rather than white. 408 * - ``V4L2_SCENE_MODE_CANDLELIGHT`` 408 * - ``V4L2_SCENE_MODE_CANDLELIGHT`` 409 - Candle light. The camera generally rai 409 - Candle light. The camera generally raises the ISO sensitivity and 410 lowers the shutter speed. This mode co 410 lowers the shutter speed. This mode compensates for relatively 411 close subject in the scene. The flash 411 close subject in the scene. The flash is disabled in order to 412 preserve the ambiance of the light. 412 preserve the ambiance of the light. 413 * - ``V4L2_SCENE_MODE_DAWN_DUSK`` 413 * - ``V4L2_SCENE_MODE_DAWN_DUSK`` 414 - Dawn and dusk. Preserves the colors se 414 - Dawn and dusk. Preserves the colors seen in low natural light 415 before dusk and after down. The camera 415 before dusk and after down. The camera may turn off the flash, and 416 automatically focus at infinity. It wi 416 automatically focus at infinity. It will usually boost saturation 417 and lower the shutter speed. 417 and lower the shutter speed. 418 * - ``V4L2_SCENE_MODE_FALL_COLORS`` 418 * - ``V4L2_SCENE_MODE_FALL_COLORS`` 419 - Fall colors. Increases saturation and 419 - Fall colors. Increases saturation and adjusts white balance for 420 color enhancement. Pictures of autumn 420 color enhancement. Pictures of autumn leaves get saturated reds 421 and yellows. 421 and yellows. 422 * - ``V4L2_SCENE_MODE_FIREWORKS`` 422 * - ``V4L2_SCENE_MODE_FIREWORKS`` 423 - Fireworks. Long exposure times are use 423 - Fireworks. Long exposure times are used to capture the expanding 424 burst of light from a firework. The ca 424 burst of light from a firework. The camera may invoke image 425 stabilization. 425 stabilization. 426 * - ``V4L2_SCENE_MODE_LANDSCAPE`` 426 * - ``V4L2_SCENE_MODE_LANDSCAPE`` 427 - Landscape. The camera may choose a sma 427 - Landscape. The camera may choose a small aperture to provide deep 428 depth of field and long exposure durat 428 depth of field and long exposure duration to help capture detail 429 in dim light conditions. The focus is 429 in dim light conditions. The focus is fixed at infinity. Suitable 430 for distant and wide scenery. 430 for distant and wide scenery. 431 * - ``V4L2_SCENE_MODE_NIGHT`` 431 * - ``V4L2_SCENE_MODE_NIGHT`` 432 - Night, also known as Night Landscape. 432 - Night, also known as Night Landscape. Designed for low light 433 conditions, it preserves detail in the 433 conditions, it preserves detail in the dark areas without blowing 434 out bright objects. The camera general 434 out bright objects. The camera generally sets itself to a 435 medium-to-high ISO sensitivity, with a 435 medium-to-high ISO sensitivity, with a relatively long exposure 436 time, and turns flash off. As such, th 436 time, and turns flash off. As such, there will be increased image 437 noise and the possibility of blurred i 437 noise and the possibility of blurred image. 438 * - ``V4L2_SCENE_MODE_PARTY_INDOOR`` 438 * - ``V4L2_SCENE_MODE_PARTY_INDOOR`` 439 - Party and indoor. Designed to capture 439 - Party and indoor. Designed to capture indoor scenes that are lit 440 by indoor background lighting as well 440 by indoor background lighting as well as the flash. The camera 441 usually increases ISO sensitivity, and 441 usually increases ISO sensitivity, and adjusts exposure for the 442 low light conditions. 442 low light conditions. 443 * - ``V4L2_SCENE_MODE_PORTRAIT`` 443 * - ``V4L2_SCENE_MODE_PORTRAIT`` 444 - Portrait. The camera adjusts the apert 444 - Portrait. The camera adjusts the aperture so that the depth of 445 field is reduced, which helps to isola 445 field is reduced, which helps to isolate the subject against a 446 smooth background. Most cameras recogn 446 smooth background. Most cameras recognize the presence of faces in 447 the scene and focus on them. The color 447 the scene and focus on them. The color hue is adjusted to enhance 448 skin tones. The intensity of the flash 448 skin tones. The intensity of the flash is often reduced. 449 * - ``V4L2_SCENE_MODE_SPORTS`` 449 * - ``V4L2_SCENE_MODE_SPORTS`` 450 - Sports. Significantly increases ISO an 450 - Sports. Significantly increases ISO and uses a fast shutter speed 451 to freeze motion of rapidly-moving sub 451 to freeze motion of rapidly-moving subjects. Increased image noise 452 may be seen in this mode. 452 may be seen in this mode. 453 * - ``V4L2_SCENE_MODE_SUNSET`` 453 * - ``V4L2_SCENE_MODE_SUNSET`` 454 - Sunset. Preserves deep hues seen in su 454 - Sunset. Preserves deep hues seen in sunsets and sunrises. It bumps 455 up the saturation. 455 up the saturation. 456 * - ``V4L2_SCENE_MODE_TEXT`` 456 * - ``V4L2_SCENE_MODE_TEXT`` 457 - Text. It applies extra contrast and sh 457 - Text. It applies extra contrast and sharpness, it is typically a 458 black-and-white mode optimized for rea 458 black-and-white mode optimized for readability. Automatic focus 459 may be switched to close-up mode and t 459 may be switched to close-up mode and this setting may also involve 460 some lens-distortion correction. 460 some lens-distortion correction. 461 461 462 .. raw:: latex 462 .. raw:: latex 463 463 464 \normalsize 464 \normalsize 465 465 466 466 467 ``V4L2_CID_3A_LOCK (bitmask)`` 467 ``V4L2_CID_3A_LOCK (bitmask)`` 468 This control locks or unlocks the automati 468 This control locks or unlocks the automatic focus, exposure and 469 white balance. The automatic adjustments c 469 white balance. The automatic adjustments can be paused independently 470 by setting the corresponding lock bit to 1 470 by setting the corresponding lock bit to 1. The camera then retains 471 the settings until the lock bit is cleared 471 the settings until the lock bit is cleared. The following lock bits 472 are defined: 472 are defined: 473 473 474 When a given algorithm is not enabled, dri 474 When a given algorithm is not enabled, drivers should ignore 475 requests to lock it and should return no e 475 requests to lock it and should return no error. An example might be 476 an application setting bit ``V4L2_LOCK_WHI 476 an application setting bit ``V4L2_LOCK_WHITE_BALANCE`` when the 477 ``V4L2_CID_AUTO_WHITE_BALANCE`` control is 477 ``V4L2_CID_AUTO_WHITE_BALANCE`` control is set to ``FALSE``. The 478 value of this control may be changed by ex 478 value of this control may be changed by exposure, white balance or 479 focus controls. 479 focus controls. 480 480 481 481 482 482 483 .. flat-table:: 483 .. flat-table:: 484 :header-rows: 0 484 :header-rows: 0 485 :stub-columns: 0 485 :stub-columns: 0 486 486 487 * - ``V4L2_LOCK_EXPOSURE`` 487 * - ``V4L2_LOCK_EXPOSURE`` 488 - Automatic exposure adjustments lock. 488 - Automatic exposure adjustments lock. 489 * - ``V4L2_LOCK_WHITE_BALANCE`` 489 * - ``V4L2_LOCK_WHITE_BALANCE`` 490 - Automatic white balance adjustments lo 490 - Automatic white balance adjustments lock. 491 * - ``V4L2_LOCK_FOCUS`` 491 * - ``V4L2_LOCK_FOCUS`` 492 - Automatic focus lock. 492 - Automatic focus lock. 493 493 494 494 495 495 496 ``V4L2_CID_PAN_SPEED (integer)`` 496 ``V4L2_CID_PAN_SPEED (integer)`` 497 This control turns the camera horizontally 497 This control turns the camera horizontally at the specific speed. 498 The unit is undefined. A positive value mo 498 The unit is undefined. A positive value moves the camera to the 499 right (clockwise when viewed from above), 499 right (clockwise when viewed from above), a negative value to the 500 left. A value of zero stops the motion if 500 left. A value of zero stops the motion if one is in progress and has 501 no effect otherwise. 501 no effect otherwise. 502 502 503 ``V4L2_CID_TILT_SPEED (integer)`` 503 ``V4L2_CID_TILT_SPEED (integer)`` 504 This control turns the camera vertically a 504 This control turns the camera vertically at the specified speed. The 505 unit is undefined. A positive value moves 505 unit is undefined. A positive value moves the camera up, a negative 506 value down. A value of zero stops the moti 506 value down. A value of zero stops the motion if one is in progress 507 and has no effect otherwise. 507 and has no effect otherwise. 508 508 509 .. _v4l2-camera-sensor-orientation: 509 .. _v4l2-camera-sensor-orientation: 510 510 511 ``V4L2_CID_CAMERA_ORIENTATION (menu)`` 511 ``V4L2_CID_CAMERA_ORIENTATION (menu)`` 512 This read-only control describes the camer 512 This read-only control describes the camera orientation by reporting its 513 mounting position on the device where the 513 mounting position on the device where the camera is installed. The control 514 value is constant and not modifiable by so 514 value is constant and not modifiable by software. This control is 515 particularly meaningful for devices which 515 particularly meaningful for devices which have a well defined orientation, 516 such as phones, laptops and portable devic 516 such as phones, laptops and portable devices since the control is expressed 517 as a position relative to the device's int 517 as a position relative to the device's intended usage orientation. For 518 example, a camera installed on the user-fa 518 example, a camera installed on the user-facing side of a phone, a tablet or 519 a laptop device is said to be have ``V4L2_ 519 a laptop device is said to be have ``V4L2_CAMERA_ORIENTATION_FRONT`` 520 orientation, while a camera installed on t 520 orientation, while a camera installed on the opposite side of the front one 521 is said to be have ``V4L2_CAMERA_ORIENTATI 521 is said to be have ``V4L2_CAMERA_ORIENTATION_BACK`` orientation. Camera 522 sensors not directly attached to the devic 522 sensors not directly attached to the device, or attached in a way that 523 allows them to move freely, such as webcam 523 allows them to move freely, such as webcams and digital cameras, are said to 524 have the ``V4L2_CAMERA_ORIENTATION_EXTERNA 524 have the ``V4L2_CAMERA_ORIENTATION_EXTERNAL`` orientation. 525 525 526 526 527 .. tabularcolumns:: |p{7.7cm}|p{9.8cm}| 527 .. tabularcolumns:: |p{7.7cm}|p{9.8cm}| 528 528 529 .. flat-table:: 529 .. flat-table:: 530 :header-rows: 0 530 :header-rows: 0 531 :stub-columns: 0 531 :stub-columns: 0 532 532 533 * - ``V4L2_CAMERA_ORIENTATION_FRONT`` 533 * - ``V4L2_CAMERA_ORIENTATION_FRONT`` 534 - The camera is oriented towards the use 534 - The camera is oriented towards the user facing side of the device. 535 * - ``V4L2_CAMERA_ORIENTATION_BACK`` 535 * - ``V4L2_CAMERA_ORIENTATION_BACK`` 536 - The camera is oriented towards the bac 536 - The camera is oriented towards the back facing side of the device. 537 * - ``V4L2_CAMERA_ORIENTATION_EXTERNAL`` 537 * - ``V4L2_CAMERA_ORIENTATION_EXTERNAL`` 538 - The camera is not directly attached to 538 - The camera is not directly attached to the device and is freely movable. 539 539 540 540 541 .. _v4l2-camera-sensor-rotation: 541 .. _v4l2-camera-sensor-rotation: 542 542 543 ``V4L2_CID_CAMERA_SENSOR_ROTATION (integer)`` 543 ``V4L2_CID_CAMERA_SENSOR_ROTATION (integer)`` 544 This read-only control describes the rotat 544 This read-only control describes the rotation correction in degrees in the 545 counter-clockwise direction to be applied 545 counter-clockwise direction to be applied to the captured images once 546 captured to memory to compensate for the c 546 captured to memory to compensate for the camera sensor mounting rotation. 547 547 548 For a precise definition of the sensor mou 548 For a precise definition of the sensor mounting rotation refer to the 549 extensive description of the 'rotation' pr 549 extensive description of the 'rotation' properties in the device tree 550 bindings file 'video-interfaces.txt'. 550 bindings file 'video-interfaces.txt'. 551 551 552 A few examples are below reported, using a 552 A few examples are below reported, using a shark swimming from left to 553 right in front of the user as the example 553 right in front of the user as the example scene to capture. :: 554 554 555 0 X-axis 555 0 X-axis 556 0 +---------------------------- 556 0 +-------------------------------------> 557 ! 557 ! 558 ! 558 ! 559 ! 559 ! 560 ! |\____)\___ 560 ! |\____)\___ 561 ! ) _____ __`< 561 ! ) _____ __`< 562 ! |/ )/ 562 ! |/ )/ 563 ! 563 ! 564 ! 564 ! 565 ! 565 ! 566 V 566 V 567 Y-axis 567 Y-axis 568 568 569 Example one - Webcam 569 Example one - Webcam 570 570 571 Assuming you can bring your laptop with yo 571 Assuming you can bring your laptop with you while swimming with sharks, 572 the camera module of the laptop is install 572 the camera module of the laptop is installed on the user facing part of a 573 laptop screen casing, and is typically use 573 laptop screen casing, and is typically used for video calls. The captured 574 images are meant to be displayed in landsc 574 images are meant to be displayed in landscape mode (width > height) on the 575 laptop screen. 575 laptop screen. 576 576 577 The camera is typically mounted upside-dow 577 The camera is typically mounted upside-down to compensate the lens optical 578 inversion effect. In this case the value o 578 inversion effect. In this case the value of the 579 V4L2_CID_CAMERA_SENSOR_ROTATION control is 579 V4L2_CID_CAMERA_SENSOR_ROTATION control is 0, no rotation is required to 580 display images correctly to the user. 580 display images correctly to the user. 581 581 582 If the camera sensor is not mounted upside 582 If the camera sensor is not mounted upside-down it is required to compensate 583 the lens optical inversion effect and the 583 the lens optical inversion effect and the value of the 584 V4L2_CID_CAMERA_SENSOR_ROTATION control is 584 V4L2_CID_CAMERA_SENSOR_ROTATION control is 180 degrees, as images will 585 result rotated when captured to memory. :: 585 result rotated when captured to memory. :: 586 586 587 +---------------------------- 587 +--------------------------------------+ 588 ! 588 ! ! 589 ! 589 ! ! 590 ! 590 ! ! 591 ! __/(_____/| 591 ! __/(_____/| ! 592 ! >.___ ____ ( 592 ! >.___ ____ ( ! 593 ! \( \| 593 ! \( \| ! 594 ! 594 ! ! 595 ! 595 ! ! 596 ! 596 ! ! 597 +---------------------------- 597 +--------------------------------------+ 598 598 599 A software rotation correction of 180 degr 599 A software rotation correction of 180 degrees has to be applied to correctly 600 display the image on the user screen. :: 600 display the image on the user screen. :: 601 601 602 +---------------------------- 602 +--------------------------------------+ 603 ! 603 ! ! 604 ! 604 ! ! 605 ! 605 ! ! 606 ! |\____)\___ 606 ! |\____)\___ ! 607 ! ) _____ __`< 607 ! ) _____ __`< ! 608 ! |/ )/ 608 ! |/ )/ ! 609 ! 609 ! ! 610 ! 610 ! ! 611 ! 611 ! ! 612 +---------------------------- 612 +--------------------------------------+ 613 613 614 Example two - Phone camera 614 Example two - Phone camera 615 615 616 It is more handy to go and swim with shark 616 It is more handy to go and swim with sharks with only your mobile phone 617 with you and take pictures with the camera 617 with you and take pictures with the camera that is installed on the back 618 side of the device, facing away from the u 618 side of the device, facing away from the user. The captured images are meant 619 to be displayed in portrait mode (height > 619 to be displayed in portrait mode (height > width) to match the device screen 620 orientation and the device usage orientati 620 orientation and the device usage orientation used when taking the picture. 621 621 622 The camera sensor is typically mounted wit 622 The camera sensor is typically mounted with its pixel array longer side 623 aligned to the device longer side, upside- 623 aligned to the device longer side, upside-down mounted to compensate for 624 the lens optical inversion effect. 624 the lens optical inversion effect. 625 625 626 The images once captured to memory will be 626 The images once captured to memory will be rotated and the value of the 627 V4L2_CID_CAMERA_SENSOR_ROTATION will repor 627 V4L2_CID_CAMERA_SENSOR_ROTATION will report a 90 degree rotation. :: 628 628 629 629 630 +---------------------------- 630 +-------------------------------------+ 631 | _ _ 631 | _ _ | 632 | \ / 632 | \ / | 633 | | | 633 | | | | 634 | | | 634 | | | | 635 | | > 635 | | > | 636 | < | 636 | < | | 637 | | | 637 | | | | 638 | . 638 | . | 639 | V 639 | V | 640 +---------------------------- 640 +-------------------------------------+ 641 641 642 A correction of 90 degrees in counter-cloc 642 A correction of 90 degrees in counter-clockwise direction has to be 643 applied to correctly display the image in 643 applied to correctly display the image in portrait mode on the device 644 screen. :: 644 screen. :: 645 645 646 +------------------- 646 +--------------------+ 647 | 647 | | 648 | 648 | | 649 | 649 | | 650 | 650 | | 651 | 651 | | 652 | 652 | | 653 | |\____)\___ 653 | |\____)\___ | 654 | ) _____ __`< 654 | ) _____ __`< | 655 | |/ )/ 655 | |/ )/ | 656 | 656 | | 657 | 657 | | 658 | 658 | | 659 | 659 | | 660 | 660 | | 661 +------------------- 661 +--------------------+ 662 662 663 663 664 .. [#f1] 664 .. [#f1] 665 This control may be changed to a menu contr 665 This control may be changed to a menu control in the future, if more 666 options are required. 666 options are required. 667 667 668 ``V4L2_CID_HDR_SENSOR_MODE (menu)`` 668 ``V4L2_CID_HDR_SENSOR_MODE (menu)`` 669 Change the sensor HDR mode. A HDR picture 669 Change the sensor HDR mode. A HDR picture is obtained by merging two 670 captures of the same scene using two diffe 670 captures of the same scene using two different exposure periods. HDR mode 671 describes the way these two captures are m 671 describes the way these two captures are merged in the sensor. 672 672 673 As modes differ for each sensor, menu item 673 As modes differ for each sensor, menu items are not standardized by this 674 control and are left to the programmer. 674 control and are left to the programmer.
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