QCameraExposureControl Class

The QCameraExposureControl class allows controlling camera exposure parameters. More...

Header: #include <QCameraExposureControl>
qmake: QT += multimedia
Inherits: QMediaControl

Public Types

enum ExposureParameter { ISO, Aperture, ShutterSpeed, ExposureCompensation, ..., ExtendedExposureParameter }

Public Functions

virtual ~QCameraExposureControl()
virtual QVariant actualValue(QCameraExposureControl::ExposureParameter parameter) const = 0
virtual bool isParameterSupported(QCameraExposureControl::ExposureParameter parameter) const = 0
virtual QVariant requestedValue(QCameraExposureControl::ExposureParameter parameter) const = 0
virtual bool setValue(QCameraExposureControl::ExposureParameter parameter, const QVariant &value) = 0
virtual QVariantList supportedParameterRange(QCameraExposureControl::ExposureParameter parameter, bool *continuous) const = 0

Signals

void actualValueChanged(int parameter)
void parameterRangeChanged(int parameter)
void requestedValueChanged(int parameter)

Protected Functions

QCameraExposureControl(QObject *parent = nullptr)

Macros

Detailed Description

The QCameraExposureControl class allows controlling camera exposure parameters.

The QCameraExposure class is the usual method of adjusting exposure related parameters when using camera functionality. This class provides a more complete but less easy to use interface, and also forms the interface to implement when writing a new implementation of QCamera functionality.

You can adjust a number of parameters that will affect images and video taken with the corresponding QCamera object - see the ExposureParameter enumeration.

The interface name of QCameraExposureControl is org.qt-project.qt.cameraexposurecontrol/5.0 as defined in QCameraExposureControl_iid.

See also QCameraExposure and QCamera.

Member Type Documentation

enum QCameraExposureControl::ExposureParameter

ConstantValueDescription
QCameraExposureControl::ISO0Camera ISO sensitivity, specified as integer value.
QCameraExposureControl::Aperture1Lens aperture is specified as an qreal F number. The supported apertures list can change depending on the focal length, in such a case the exposureParameterRangeChanged() signal is emitted.
QCameraExposureControl::ShutterSpeed2Shutter speed in seconds, specified as qreal.
QCameraExposureControl::ExposureCompensation3Exposure compensation, specified as qreal EV value.
QCameraExposureControl::FlashPower4Manual flash power, specified as qreal value. Accepted power range is [0..1.0], with 0 value means no flash and 1.0 corresponds to full flash power.

This value is only used in the manual flash mode.

ConstantValueDescription
QCameraExposureControl::TorchPower6Manual torch power, specified as qreal value. Accepted power range is [0..1.0], with 0 value means no light and 1.0 corresponds to full torch power.

This value is only used in the torch flash mode.

ConstantValueDescription
QCameraExposureControl::FlashCompensation5Flash compensation, specified as qreal EV value.
QCameraExposureControl::SpotMeteringPoint7The relative frame coordinate of the point to use for exposure metering in spot metering mode, specified as a QPointF.
QCameraExposureControl::ExposureMode8Camera exposure mode.
QCameraExposureControl::MeteringMode9Camera metering mode.
QCameraExposureControl::ExtendedExposureParameter1000The base value for platform specific extended parameters. For such parameters the sequential values starting from ExtendedExposureParameter should be used.

Member Function Documentation

[protected] QCameraExposureControl::QCameraExposureControl(QObject *parent = nullptr)

Constructs a camera exposure control object with parent.

[virtual] QCameraExposureControl::~QCameraExposureControl()

Destroys the camera exposure control object.

[pure virtual] QVariant QCameraExposureControl::actualValue(QCameraExposureControl::ExposureParameter parameter) const

[signal] void QCameraExposureControl::actualValueChanged(int parameter)

[pure virtual] bool QCameraExposureControl::isParameterSupported(QCameraExposureControl::ExposureParameter parameter) const

[signal] void QCameraExposureControl::parameterRangeChanged(int parameter)

[pure virtual] QVariant QCameraExposureControl::requestedValue(QCameraExposureControl::ExposureParameter parameter) const

[signal] void QCameraExposureControl::requestedValueChanged(int parameter)

[pure virtual] bool QCameraExposureControl::setValue(QCameraExposureControl::ExposureParameter parameter, const QVariant &value)

[pure virtual] QVariantList QCameraExposureControl::supportedParameterRange(QCameraExposureControl::ExposureParameter parameter, bool *continuous) const

Macro Documentation

QCameraExposureControl_iid

org.qt-project.qt.cameraexposurecontrol/5.0

Defines the interface name of the QCameraExposureControl class.