libcamera v0.0.0+1-cfe3b8aa
Supporting cameras in Linux since 2019
Namespaces | Enumerations | Variables
libcamera::controls Namespace Reference

Namespace for libcamera controls. More...

Namespaces

namespace  draft
 Namespace for libcamera draft controls.
 

Enumerations

enum  {
  AE_ENABLE = 1 , AE_LOCKED = 2 , AE_METERING_MODE = 3 , AE_CONSTRAINT_MODE = 4 ,
  AE_EXPOSURE_MODE = 5 , EXPOSURE_VALUE = 6 , EXPOSURE_TIME = 7 , ANALOGUE_GAIN = 8 ,
  BRIGHTNESS = 9 , CONTRAST = 10 , LUX = 11 , AWB_ENABLE = 12 ,
  AWB_MODE = 13 , AWB_LOCKED = 14 , COLOUR_GAINS = 15 , COLOUR_TEMPERATURE = 16 ,
  SATURATION = 17 , SENSOR_BLACK_LEVELS = 18 , SHARPNESS = 19 , FOCUS_FO_M = 20 ,
  COLOUR_CORRECTION_MATRIX = 21 , SCALER_CROP = 22 , DIGITAL_GAIN = 23 , FRAME_DURATION = 24 ,
  FRAME_DURATION_LIMITS = 25 , SENSOR_TIMESTAMP = 26 , AE_PRECAPTURE_TRIGGER = 27 , AF_TRIGGER = 28 ,
  NOISE_REDUCTION_MODE = 29 , COLOR_CORRECTION_ABERRATION_MODE = 30 , AE_STATE = 31 , AF_STATE = 32 ,
  AWB_STATE = 33 , SENSOR_ROLLING_SHUTTER_SKEW = 34 , LENS_SHADING_MAP_MODE = 35 , SCENE_FLICKER = 36 ,
  PIPELINE_DEPTH = 37 , MAX_LATENCY = 38 , TEST_PATTERN_MODE = 39
}
 
enum  AeMeteringModeEnum { MeteringCentreWeighted = 0 , MeteringSpot = 1 , MeteringMatrix = 2 , MeteringCustom = 3 }
 Supported AeMeteringMode values. More...
 
enum  AeConstraintModeEnum { ConstraintNormal = 0 , ConstraintHighlight = 1 , ConstraintShadows = 2 , ConstraintCustom = 3 }
 Supported AeConstraintMode values. More...
 
enum  AeExposureModeEnum { ExposureNormal = 0 , ExposureShort = 1 , ExposureLong = 2 , ExposureCustom = 3 }
 Supported AeExposureMode values. More...
 
enum  AwbModeEnum {
  AwbAuto = 0 , AwbIncandescent = 1 , AwbTungsten = 2 , AwbFluorescent = 3 ,
  AwbIndoor = 4 , AwbDaylight = 5 , AwbCloudy = 6 , AwbCustom = 7
}
 Supported AwbMode values. More...
 

Variables

const Control< bool > AeEnable
 Enable or disable the AE. More...
 
const Control< bool > AeLocked
 Report the lock status of a running AE algorithm. More...
 
const std::array< const ControlValue, 4 > AeMeteringModeValues
 List of all AeMeteringMode supported values.
 
const Control< int32_t > AeMeteringMode
 Specify a metering mode for the AE algorithm to use. The metering modes determine which parts of the image are used to determine the scene brightness. Metering modes may be platform specific and not all metering modes may be supported.
 
const std::array< const ControlValue, 4 > AeConstraintModeValues
 List of all AeConstraintMode supported values.
 
const Control< int32_t > AeConstraintMode
 Specify a constraint mode for the AE algorithm to use. These determine how the measured scene brightness is adjusted to reach the desired target exposure. Constraint modes may be platform specific, and not all constraint modes may be supported.
 
const std::array< const ControlValue, 4 > AeExposureModeValues
 List of all AeExposureMode supported values.
 
const Control< int32_t > AeExposureMode
 Specify an exposure mode for the AE algorithm to use. These specify how the desired total exposure is divided between the shutter time and the sensor's analogue gain. The exposure modes are platform specific, and not all exposure modes may be supported.
 
const Control< float > ExposureValue
 Specify an Exposure Value (EV) parameter. The EV parameter will only be applied if the AE algorithm is currently enabled. More...
 
const Control< int32_t > ExposureTime
 Exposure time (shutter speed) for the frame applied in the sensor device. This value is specified in micro-seconds. More...
 
const Control< float > AnalogueGain
 Analogue gain value applied in the sensor device. The value of the control specifies the gain multiplier applied to all colour channels. This value cannot be lower than 1.0. More...
 
const Control< float > Brightness
 Specify a fixed brightness parameter. Positive values (up to 1.0) produce brighter images; negative values (up to -1.0) produce darker images and 0.0 leaves pixels unchanged.
 
const Control< float > Contrast
 Specify a fixed contrast parameter. Normal contrast is given by the value 1.0; larger values produce images with more contrast.
 
const Control< float > Lux
 Report an estimate of the current illuminance level in lux. The Lux control can only be returned in metadata.
 
const Control< bool > AwbEnable
 Enable or disable the AWB. More...
 
const std::array< const ControlValue, 8 > AwbModeValues
 List of all AwbMode supported values.
 
const Control< int32_t > AwbMode
 Specify the range of illuminants to use for the AWB algorithm. The modes supported are platform specific, and not all modes may be supported.
 
const Control< bool > AwbLocked
 Report the lock status of a running AWB algorithm. More...
 
const Control< Span< const float > > ColourGains
 Pair of gain values for the Red and Blue colour channels, in that order. ColourGains can only be applied in a Request when the AWB is disabled. More...
 
const Control< int32_t > ColourTemperature
 Report the current estimate of the colour temperature, in kelvin, for this frame. The ColourTemperature control can only be returned in metadata.
 
const Control< float > Saturation
 Specify a fixed saturation parameter. Normal saturation is given by the value 1.0; larger values produce more saturated colours; 0.0 produces a greyscale image.
 
const Control< Span< const int32_t > > SensorBlackLevels
 Reports the sensor black levels used for processing a frame, in the order R, Gr, Gb, B. These values are returned as numbers out of a 16-bit pixel range (as if pixels ranged from 0 to 65535). The SensorBlackLevels control can only be returned in metadata.
 
const Control< float > Sharpness
 A value of 0.0 means no sharpening. The minimum value means minimal sharpening, and shall be 0.0 unless the camera can't disable sharpening completely. The default value shall give a "reasonable" level of sharpening, suitable for most use cases. The maximum value may apply extremely high levels of sharpening, higher than anyone could reasonably want. Negative values are not allowed. Note also that sharpening is not applied to raw streams.
 
const Control< int32_t > FocusFoM
 Reports a Figure of Merit (FoM) to indicate how in-focus the frame is. A larger FocusFoM value indicates a more in-focus frame. This control depends on the IPA to gather ISP statistics from the defined focus region, and combine them in a suitable way to generate a FocusFoM value. In this respect, it is not necessarily aimed at providing a way to implement a focus algorithm by the application, rather an indication of how in-focus a frame is.
 
const Control< Span< const float > > ColourCorrectionMatrix
 The 3x3 matrix that converts camera RGB to sRGB within the imaging pipeline. This should describe the matrix that is used after pixels have been white-balanced, but before any gamma transformation. The 3x3 matrix is stored in conventional reading order in an array of 9 floating point values.
 
const Control< RectangleScalerCrop
 Sets the image portion that will be scaled to form the whole of the final output image. The (x,y) location of this rectangle is relative to the PixelArrayActiveAreas that is being used. The units remain native sensor pixels, even if the sensor is being used in a binning or skipping mode. More...
 
const Control< float > DigitalGain
 Digital gain value applied during the processing steps applied to the image as captured from the sensor. More...
 
const Control< int64_t > FrameDuration
 The instantaneous frame duration from start of frame exposure to start of next exposure, expressed in microseconds. This control is meant to be returned in metadata.
 
const Control< Span< const int64_t > > FrameDurationLimits
 The minimum and maximum (in that order) frame duration, expressed in microseconds. More...
 
const Control< int64_t > SensorTimestamp
 The time when the first row of the image sensor active array is exposed. More...
 
const ControlIdMap controls
 List of all supported libcamera controls. More...
 

Detailed Description

Namespace for libcamera controls.

Enumeration Type Documentation

◆ AeConstraintModeEnum

Supported AeConstraintMode values.

Enumerator
ConstraintNormal 

Default constraint mode. This mode aims to balance the exposure of different parts of the image so as to reach a reasonable average level. However, highlights in the image may appear over-exposed and lowlights may appear under-exposed.

ConstraintHighlight 

Highlight constraint mode. This mode adjusts the exposure levels in order to try and avoid over-exposing the brightest parts (highlights) of an image. Other non-highlight parts of the image may appear under-exposed.

ConstraintShadows 

Shadows constraint mode. This mode adjusts the exposure levels in order to try and avoid under-exposing the dark parts (shadows) of an image. Other normally exposed parts of the image may appear over-exposed.

ConstraintCustom 

Custom constraint mode.

◆ AeExposureModeEnum

Supported AeExposureMode values.

Enumerator
ExposureNormal 

Default exposure mode.

ExposureShort 

Exposure mode allowing only short exposure times.

ExposureLong 

Exposure mode allowing long exposure times.

ExposureCustom 

Custom exposure mode.

◆ AeMeteringModeEnum

Supported AeMeteringMode values.

Enumerator
MeteringCentreWeighted 

Centre-weighted metering mode.

MeteringSpot 

Spot metering mode.

MeteringMatrix 

Matrix metering mode.

MeteringCustom 

Custom metering mode.

◆ AwbModeEnum

Supported AwbMode values.

Enumerator
AwbAuto 

Search over the whole colour temperature range.

AwbIncandescent 

Incandescent AWB lamp mode.

AwbTungsten 

Tungsten AWB lamp mode.

AwbFluorescent 

Fluorescent AWB lamp mode.

AwbIndoor 

Indoor AWB lighting mode.

AwbDaylight 

Daylight AWB lighting mode.

AwbCloudy 

Cloudy AWB lighting mode.

AwbCustom 

Custom AWB mode.

Variable Documentation

◆ AeEnable

libcamera::controls::AeEnable
extern

Enable or disable the AE.

See also
ExposureTime AnalogueGain

◆ AeLocked

libcamera::controls::AeLocked
extern

Report the lock status of a running AE algorithm.

If the AE algorithm is locked the value shall be set to true, if it's converging it shall be set to false. If the AE algorithm is not running the control shall not be present in the metadata control list.

See also
AeEnable

◆ AnalogueGain

libcamera::controls::AnalogueGain
extern

Analogue gain value applied in the sensor device. The value of the control specifies the gain multiplier applied to all colour channels. This value cannot be lower than 1.0.

Setting this value means that it is now fixed and the AE algorithm may not change it. Setting it back to zero returns it to the control of the AE algorithm.

See also
ExposureTime AeEnable
Todo:
Document the interactions between AeEnable and setting a fixed value for this control. Consider interactions with other AE features, such as aperture and aperture/shutter priority mode, and decide if control of which features should be automatically adjusted shouldn't better be handled through a separate AE mode control.

◆ AwbEnable

libcamera::controls::AwbEnable
extern

Enable or disable the AWB.

See also
ColourGains

◆ AwbLocked

libcamera::controls::AwbLocked
extern

Report the lock status of a running AWB algorithm.

If the AWB algorithm is locked the value shall be set to true, if it's converging it shall be set to false. If the AWB algorithm is not running the control shall not be present in the metadata control list.

See also
AwbEnable

◆ ColourGains

libcamera::controls::ColourGains
extern

Pair of gain values for the Red and Blue colour channels, in that order. ColourGains can only be applied in a Request when the AWB is disabled.

See also
AwbEnable

◆ controls

const ControlIdMap libcamera::controls::controls
extern

List of all supported libcamera controls.

Unless otherwise stated, all controls are bi-directional, i.e. they can be set through Request::controls() and returned out through Request::metadata().

◆ DigitalGain

libcamera::controls::DigitalGain
extern

Digital gain value applied during the processing steps applied to the image as captured from the sensor.

The global digital gain factor is applied to all the colour channels of the RAW image. Different pipeline models are free to specify how the global gain factor applies to each separate channel.

If an imaging pipeline applies digital gain in distinct processing steps, this value indicates their total sum. Pipelines are free to decide how to adjust each processing step to respect the received gain factor and shall report their total value in the request metadata.

◆ ExposureTime

libcamera::controls::ExposureTime
extern

Exposure time (shutter speed) for the frame applied in the sensor device. This value is specified in micro-seconds.

Setting this value means that it is now fixed and the AE algorithm may not change it. Setting it back to zero returns it to the control of the AE algorithm.

See also
AnalogueGain AeEnable
Todo:
Document the interactions between AeEnable and setting a fixed value for this control. Consider interactions with other AE features, such as aperture and aperture/shutter priority mode, and decide if control of which features should be automatically adjusted shouldn't better be handled through a separate AE mode control.

◆ ExposureValue

libcamera::controls::ExposureValue
extern

Specify an Exposure Value (EV) parameter. The EV parameter will only be applied if the AE algorithm is currently enabled.

By convention EV adjusts the exposure as log2. For example EV = [-2, -1, 0.5, 0, 0.5, 1, 2] results in an exposure adjustment of [1/4x, 1/2x, 1/sqrt(2)x, 1x, sqrt(2)x, 2x, 4x].

See also
AeEnable

◆ FrameDurationLimits

libcamera::controls::FrameDurationLimits
extern

The minimum and maximum (in that order) frame duration, expressed in microseconds.

When provided by applications, the control specifies the sensor frame duration interval the pipeline has to use. This limits the largest exposure time the sensor can use. For example, if a maximum frame duration of 33ms is requested (corresponding to 30 frames per second), the sensor will not be able to raise the exposure time above 33ms. A fixed frame duration is achieved by setting the minimum and maximum values to be the same. Setting both values to 0 reverts to using the IPA provided defaults.

The maximum frame duration provides the absolute limit to the shutter speed computed by the AE algorithm and it overrides any exposure mode setting specified with controls::AeExposureMode. Similarly, when a manual exposure time is set through controls::ExposureTime, it also gets clipped to the limits set by this control. When reported in metadata, the control expresses the minimum and maximum frame durations used after being clipped to the sensor provided frame duration limits.

See also
AeExposureMode
ExposureTime
Todo:
Define how to calculate the capture frame rate by defining controls to report additional delays introduced by the capture pipeline or post-processing stages (ie JPEG conversion, frame scaling).
Todo:
Provide an explicit definition of default control values, for this and all other controls.

◆ ScalerCrop

libcamera::controls::ScalerCrop
extern

Sets the image portion that will be scaled to form the whole of the final output image. The (x,y) location of this rectangle is relative to the PixelArrayActiveAreas that is being used. The units remain native sensor pixels, even if the sensor is being used in a binning or skipping mode.

This control is only present when the pipeline supports scaling. Its maximum valid value is given by the properties::ScalerCropMaximum property, and the two can be used to implement digital zoom.

◆ SensorTimestamp

libcamera::controls::SensorTimestamp
extern

The time when the first row of the image sensor active array is exposed.

The timestamp, expressed in nanoseconds, represents a monotonically increasing counter since the system boot time, as defined by the Linux-specific CLOCK_BOOTTIME clock id.

The SensorTimestamp control can only be returned in metadata.

Todo:
Define how the sensor timestamp has to be used in the reprocessing use case.