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|
# SPDX-License-Identifier: LGPL-2.1-or-later
#
# Copyright (C) 2019, Google Inc.
#
%YAML 1.1
---
# Unless otherwise stated, all controls are bi-directional, i.e. they can be
# set through Request::controls() and returned out through Request::metadata().
vendor: libcamera
controls:
- AeEnable:
type: bool
description: |
Enable or disable the AE.
\sa ExposureTime AnalogueGain
- AeLocked:
type: bool
description: |
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.
\sa AeEnable
# AeMeteringMode needs further attention:
# - Auto-generate max enum value.
# - Better handling of custom types.
- AeMeteringMode:
type: int32_t
description: |
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.
enum:
- name: MeteringCentreWeighted
value: 0
description: Centre-weighted metering mode.
- name: MeteringSpot
value: 1
description: Spot metering mode.
- name: MeteringMatrix
value: 2
description: Matrix metering mode.
- name: MeteringCustom
value: 3
description: Custom metering mode.
# AeConstraintMode needs further attention:
# - Auto-generate max enum value.
# - Better handling of custom types.
- AeConstraintMode:
type: int32_t
description: |
Specify a constraint mode for the AE algorithm to use.
The constraint modes 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.
enum:
- name: ConstraintNormal
value: 0
description: |
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.
- name: ConstraintHighlight
value: 1
description: |
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.
- name: ConstraintShadows
value: 2
description: |
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.
- name: ConstraintCustom
value: 3
description: |
Custom constraint mode.
# AeExposureMode needs further attention:
# - Auto-generate max enum value.
# - Better handling of custom types.
- AeExposureMode:
type: int32_t
description: |
Specify an exposure mode for the AE algorithm to use.
The exposure modes specify how the desired total exposure is divided
between the shutter time and the sensor's analogue gain. They are
platform specific, and not all exposure modes may be supported.
enum:
- name: ExposureNormal
value: 0
description: Default exposure mode.
- name: ExposureShort
value: 1
description: Exposure mode allowing only short exposure times.
- name: ExposureLong
value: 2
description: Exposure mode allowing long exposure times.
- name: ExposureCustom
value: 3
description: Custom exposure mode.
- ExposureValue:
type: float
description: |
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].
\sa AeEnable
- ExposureTime:
type: int32_t
description: |
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.
\sa 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.
- AnalogueGain:
type: float
description: |
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.
\sa 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.
- AeFlickerMode:
type: int32_t
description: |
Set the flicker avoidance mode for AGC/AEC.
The flicker mode determines whether, and how, the AGC/AEC algorithm
attempts to hide flicker effects caused by the duty cycle of artificial
lighting.
Although implementation dependent, many algorithms for "flicker
avoidance" work by restricting this exposure time to integer multiples
of the cycle period, wherever possible.
Implementations may not support all of the flicker modes listed below.
By default the system will start in FlickerAuto mode if this is
supported, otherwise the flicker mode will be set to FlickerOff.
enum:
- name: FlickerOff
value: 0
description: |
No flicker avoidance is performed.
- name: FlickerManual
value: 1
description: |
Manual flicker avoidance.
Suppress flicker effects caused by lighting running with a period
specified by the AeFlickerPeriod control.
\sa AeFlickerPeriod
- name: FlickerAuto
value: 2
description: |
Automatic flicker period detection and avoidance.
The system will automatically determine the most likely value of
flicker period, and avoid flicker of this frequency. Once flicker
is being corrected, it is implementation dependent whether the
system is still able to detect a change in the flicker period.
\sa AeFlickerDetected
- AeFlickerPeriod:
type: int32_t
description: |
Manual flicker period in microseconds.
This value sets the current flicker period to avoid. It is used when
AeFlickerMode is set to FlickerManual.
To cancel 50Hz mains flicker, this should be set to 10000 (corresponding
to 100Hz), or 8333 (120Hz) for 60Hz mains.
Setting the mode to FlickerManual when no AeFlickerPeriod has ever been
set means that no flicker cancellation occurs (until the value of this
control is updated).
Switching to modes other than FlickerManual has no effect on the
value of the AeFlickerPeriod control.
\sa AeFlickerMode
- AeFlickerDetected:
type: int32_t
description: |
Flicker period detected in microseconds.
The value reported here indicates the currently detected flicker
period, or zero if no flicker at all is detected.
When AeFlickerMode is set to FlickerAuto, there may be a period during
which the value reported here remains zero. Once a non-zero value is
reported, then this is the flicker period that has been detected and is
now being cancelled.
In the case of 50Hz mains flicker, the value would be 10000
(corresponding to 100Hz), or 8333 (120Hz) for 60Hz mains flicker.
It is implementation dependent whether the system can continue to detect
flicker of different periods when another frequency is already being
cancelled.
\sa AeFlickerMode
- Brightness:
type: float
description: |
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.
- Contrast:
type: float
description: |
Specify a fixed contrast parameter.
Normal contrast is given by the value 1.0; larger values produce images
with more contrast.
- Lux:
type: float
description: |
Report an estimate of the current illuminance level in lux.
The Lux control can only be returned in metadata.
- AwbEnable:
type: bool
description: |
Enable or disable the AWB.
\sa ColourGains
# AwbMode needs further attention:
# - Auto-generate max enum value.
# - Better handling of custom types.
- AwbMode:
type: int32_t
description: |
Specify the range of illuminants to use for the AWB algorithm.
The modes supported are platform specific, and not all modes may be
supported.
enum:
- name: AwbAuto
value: 0
description: Search over the whole colour temperature range.
- name: AwbIncandescent
value: 1
description: Incandescent AWB lamp mode.
- name: AwbTungsten
value: 2
description: Tungsten AWB lamp mode.
- name: AwbFluorescent
value: 3
description: Fluorescent AWB lamp mode.
- name: AwbIndoor
value: 4
description: Indoor AWB lighting mode.
- name: AwbDaylight
value: 5
description: Daylight AWB lighting mode.
- name: AwbCloudy
value: 6
description: Cloudy AWB lighting mode.
- name: AwbCustom
value: 7
description: Custom AWB mode.
- AwbLocked:
type: bool
description: |
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.
\sa AwbEnable
- ColourGains:
type: float
description: |
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.
\sa AwbEnable
size: [2]
- ColourTemperature:
type: int32_t
description: |
Report the estimate of the colour temperature for the frame, in kelvin.
The ColourTemperature control can only be returned in metadata.
- Saturation:
type: float
description: |
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.
- SensorBlackLevels:
type: int32_t
description: |
Reports the sensor black levels used for processing a frame.
The values are in the order R, Gr, Gb, B. They 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.
size: [4]
- Sharpness:
type: float
description: |
Intensity of the sharpening applied to the image.
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.
- FocusFoM:
type: int32_t
description: |
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 singular
value may be based on a combination of statistics gathered from
multiple focus regions within an image. The number of focus regions and
method of combination is platform dependent. 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.
- ColourCorrectionMatrix:
type: float
description: |
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.
size: [3,3]
- ScalerCrop:
type: Rectangle
description: |
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.
- DigitalGain:
type: float
description: |
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.
- FrameDuration:
type: int64_t
description: |
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.
- FrameDurationLimits:
type: int64_t
description: |
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
camera 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.
\sa AeExposureMode
\sa 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.
size: [2]
- SensorTemperature:
type: float
description: |
Temperature measure from the camera sensor in Celsius.
This value is typically obtained by a thermal sensor present on-die or
in the camera module. The range of reported temperatures is device
dependent.
The SensorTemperature control will only be returned in metadata if a
thermal sensor is present.
- SensorTimestamp:
type: int64_t
description: |
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.
- AfMode:
type: int32_t
description: |
The mode of the AF (autofocus) algorithm.
An implementation may choose not to implement all the modes.
enum:
- name: AfModeManual
value: 0
description: |
The AF algorithm is in manual mode.
In this mode it will never perform any action nor move the lens of
its own accord, but an application can specify the desired lens
position using the LensPosition control. The AfState will always
report AfStateIdle.
If the camera is started in AfModeManual, it will move the focus
lens to the position specified by the LensPosition control.
This mode is the recommended default value for the AfMode control.
External cameras (as reported by the Location property set to
CameraLocationExternal) may use a different default value.
- name: AfModeAuto
value: 1
description: |
The AF algorithm is in auto mode.
In this mode the algorithm will never move the lens or change state
unless the AfTrigger control is used. The AfTrigger control can be
used to initiate a focus scan, the results of which will be
reported by AfState.
If the autofocus algorithm is moved from AfModeAuto to another mode
while a scan is in progress, the scan is cancelled immediately,
without waiting for the scan to finish.
When first entering this mode the AfState will report AfStateIdle.
When a trigger control is sent, AfState will report AfStateScanning
for a period before spontaneously changing to AfStateFocused or
AfStateFailed, depending on the outcome of the scan. It will remain
in this state until another scan is initiated by the AfTrigger
control. If a scan is cancelled (without changing to another mode),
AfState will return to AfStateIdle.
- name: AfModeContinuous
value: 2
description: |
The AF algorithm is in continuous mode.
In this mode the lens can re-start a scan spontaneously at any
moment, without any user intervention. The AfState still reports
whether the algorithm is currently scanning or not, though the
application has no ability to initiate or cancel scans, nor to move
the lens for itself.
However, applications can pause the AF algorithm from continuously
scanning by using the AfPause control. This allows video or still
images to be captured whilst guaranteeing that the focus is fixed.
When set to AfModeContinuous, the system will immediately initiate a
scan so AfState will report AfStateScanning, and will settle on one
of AfStateFocused or AfStateFailed, depending on the scan result.
- AfRange:
type: int32_t
description: |
The range of focus distances that is scanned.
An implementation may choose not to implement all the options here.
enum:
- name: AfRangeNormal
value: 0
description: |
A wide range of focus distances is scanned.
Scanned distances cover all the way from infinity down to close
distances, though depending on the implementation, possibly not
including the very closest macro positions.
- name: AfRangeMacro
value: 1
description: |
Only close distances are scanned.
- name: AfRangeFull
value: 2
description: |
The full range of focus distances is scanned.
This range is similar to AfRangeNormal but includes the very
closest macro positions.
- AfSpeed:
type: int32_t
description: |
Determine whether the AF is to move the lens as quickly as possible or
more steadily.
For example, during video recording it may be desirable not to move the
lens too abruptly, but when in a preview mode (waiting for a still
capture) it may be helpful to move the lens as quickly as is reasonably
possible.
enum:
- name: AfSpeedNormal
value: 0
description: Move the lens at its usual speed.
- name: AfSpeedFast
value: 1
description: Move the lens more quickly.
- AfMetering:
type: int32_t
description: |
The parts of the image used by the AF algorithm to measure focus.
enum:
- name: AfMeteringAuto
value: 0
description: |
Let the AF algorithm decide for itself where it will measure focus.
- name: AfMeteringWindows
value: 1
description: |
Use the rectangles defined by the AfWindows control to measure focus.
If no windows are specified the behaviour is platform dependent.
- AfWindows:
type: Rectangle
description: |
The focus windows used by the AF algorithm when AfMetering is set to
AfMeteringWindows.
The units used are pixels within the rectangle returned by the
ScalerCropMaximum property.
In order to be activated, a rectangle must be programmed with non-zero
width and height. Internally, these rectangles are intersected with the
ScalerCropMaximum rectangle. If the window becomes empty after this
operation, then the window is ignored. If all the windows end up being
ignored, then the behaviour is platform dependent.
On platforms that support the ScalerCrop control (for implementing
digital zoom, for example), no automatic recalculation or adjustment of
AF windows is performed internally if the ScalerCrop is changed. If any
window lies outside the output image after the scaler crop has been
applied, it is up to the application to recalculate them.
The details of how the windows are used are platform dependent. We note
that when there is more than one AF window, a typical implementation
might find the optimal focus position for each one and finally select
the window where the focal distance for the objects shown in that part
of the image are closest to the camera.
size: [n]
- AfTrigger:
type: int32_t
description: |
Start an autofocus scan.
This control starts an autofocus scan when AfMode is set to AfModeAuto,
and is ignored if AfMode is set to AfModeManual or AfModeContinuous. It
can also be used to terminate a scan early.
enum:
- name: AfTriggerStart
value: 0
description: |
Start an AF scan.
Setting the control to AfTriggerStart is ignored if a scan is in
progress.
- name: AfTriggerCancel
value: 1
description: |
Cancel an AF scan.
This does not cause the lens to move anywhere else. Ignored if no
scan is in progress.
- AfPause:
type: int32_t
description: |
Pause lens movements when in continuous autofocus mode.
This control has no effect except when in continuous autofocus mode
(AfModeContinuous). It can be used to pause any lens movements while
(for example) images are captured. The algorithm remains inactive
until it is instructed to resume.
enum:
- name: AfPauseImmediate
value: 0
description: |
Pause the continuous autofocus algorithm immediately.
The autofocus algorithm is paused whether or not any kind of scan
is underway. AfPauseState will subsequently report
AfPauseStatePaused. AfState may report any of AfStateScanning,
AfStateFocused or AfStateFailed, depending on the algorithm's state
when it received this control.
- name: AfPauseDeferred
value: 1
description: |
Pause the continuous autofocus algorithm at the end of the scan.
This is similar to AfPauseImmediate, and if the AfState is
currently reporting AfStateFocused or AfStateFailed it will remain
in that state and AfPauseState will report AfPauseStatePaused.
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