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QCameraDevice Class

The QCameraDevice class provides general information about camera devices. More...

Header: #include <QCameraDevice>
CMake: find_package(Qt6 REQUIRED COMPONENTS Multimedia)
target_link_libraries(mytarget PRIVATE Qt6::Multimedia)
qmake: QT += multimedia

Public Types

enum Position { UnspecifiedPosition, BackFace, FrontFace }

Properties

Public Functions

QCameraDevice()
QCameraDevice(const QCameraDevice &other)
~QCameraDevice()
QtVideo::Rotation correctionAngle() const
QString description() const
QByteArray id() const
bool isDefault() const
bool isNull() const
QList<QSize> photoResolutions() const
QCameraDevice::Position position() const
QList<QCameraFormat> videoFormats() const
bool operator!=(const QCameraDevice &other) const
QCameraDevice &operator=(const QCameraDevice &other)
bool operator==(const QCameraDevice &other) const

Detailed Description

QCameraDevice represents a physical camera device and its properties.

You can discover what cameras are available on a system using the availableCameras() and defaultCamera() functions. These are contained within QtMultimedia::MediaDevices.

This example prints the name of all available cameras:

const QList<QCameraDevice> cameras = QMediaDevices::videoInputs();
for (const QCameraDevice &cameraDevice : cameras)
    qDebug() << cameraDevice.description();

A QCameraDevice can be used to construct a QCamera. The following example instantiates a QCamera whose camera device is named mycamera:

const QList<QCameraDevice> cameras = QMediaDevices::videoInputs();
for (const QCameraDevice &cameraDevice : cameras) {
    if (cameraDevice.description() == "mycamera")
        camera = new QCamera(cameraDevice);
}

You can also use QCameraDevice to get general information about a camera device such as description and physical position on the system.

QCamera myCamera;
QCameraDevice cameraDevice = camera->cameraDevice();

if (cameraDevice.position() == QCameraDevice::FrontFace)
    qDebug() << "The camera is on the front face of the hardware system.";
else if (cameraDevice.position() == QCameraDevice::BackFace)
    qDebug() << "The camera is on the back face of the hardware system.";

See also QCamera.

Member Type Documentation

enum QCameraDevice::Position

This enum specifies the physical position of the camera on the system hardware.

ConstantValueDescription
QCameraDevice::UnspecifiedPosition0The camera position is unspecified or unknown.
QCameraDevice::BackFace1The camera is on the back face of the system hardware. For example on a mobile device, it means it is on the opposite side to that of the screen.
QCameraDevice::FrontFace2The camera is on the front face of the system hardware. For example on a mobile device, it means it is on the same side as that of the screen. Front-facing cameras generate video frames with the property QVideoFrame::mirrored set to true. This means that the presentation of these frames is flipped around the vertical axis to display the video output as a mirror, whereas recording only considers the transformations of the surface specified in QVideoFrame::surfaceFormat.

See also position().

Property Documentation

[read-only, since 6.7] correctionAngle : const QtVideo::Rotation

Returns the rotation angle needed to compensate for the physical camera rotation of the camera compared to its native orientation. In other words, the property represents the clockwise angle through which the output image needs to be rotated to be upright on the device screen in its native orientation. Since correctionAngle is relative to the native orientation, this value does not change with altering the device orientation (portrait/landscape). The correction angle may be non-zero mostly on Android, where native and camera orientations are defined by the manufacturer.

Example with 90 degrees \a correctionAngle

This property was introduced in Qt 6.7.

Access functions:

QtVideo::Rotation correctionAngle() const

[read-only] description : const QString

Returns the human-readable description of the camera.

Use this string to present the device to the user.

Access functions:

QString description() const

[read-only] id : const QByteArray

Returns the device id of the camera

This is a unique ID to identify the camera and may not be human-readable.

Access functions:

QByteArray id() const

[read-only] isDefault : const bool

Returns true if this is the default camera device.

Access functions:

bool isDefault() const

[read-only] position : const Position

Returns the physical position of the camera on the hardware system.

Access functions:

QCameraDevice::Position position() const

[read-only] videoFormats : const QList<QCameraFormat>

Returns the video formats supported by the camera.

Access functions:

QList<QCameraFormat> videoFormats() const

Member Function Documentation

QCameraDevice::QCameraDevice()

Constructs a null camera device

QCameraDevice::QCameraDevice(const QCameraDevice &other)

Constructs a copy of other.

[noexcept] QCameraDevice::~QCameraDevice()

Destroys the QCameraDevice.

bool QCameraDevice::isNull() const

Returns true if this QCameraDevice is null or invalid.

QList<QSize> QCameraDevice::photoResolutions() const

Returns a list of resolutions that the camera can use to capture still images.

See also QImageCapture.

bool QCameraDevice::operator!=(const QCameraDevice &other) const

Returns true if this QCameraDevice is different from other.

QCameraDevice &QCameraDevice::operator=(const QCameraDevice &other)

Sets the QCameraDevice object to be equal to other.

bool QCameraDevice::operator==(const QCameraDevice &other) const

Returns true if this QCameraDevice is equal to other.

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