path: root/src/multimedia/camera/qcamera.cpp

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#include "qcamera_p.h"

#include <qcamerainfo.h>
#include <private/qplatformcamera_p.h>
#include <private/qplatformcameraexposure_p.h>
#include <private/qplatformcamerafocus_p.h>
#include <private/qplatformcameraimageprocessing_p.h>
#include <private/qplatformcameraimagecapture_p.h>
#include <private/qplatformmediaintegration_p.h>
#include <private/qplatformmediacapture_p.h>
#include <qmediadevices.h>
#include <qmediacapturesession.h>

#include <QDebug>

QT_BEGIN_NAMESPACE

/*!
    \class QCamera


    \brief The QCamera class provides interface for system camera devices.

    \inmodule QtMultimedia
    \ingroup multimedia
    \ingroup multimedia_camera

    QCamera can be used within a QMediaCaptureSession for video recording and image taking.

    You can use QCameraInfo to list available cameras and choose which one to use.

    \snippet multimedia-snippets/camera.cpp Camera selection

    On hardware that supports it, QCamera lets you adjust the focus
    and zoom. This also includes things
    like "Macro" mode for close up work (e.g. reading barcodes, or
    recognising letters), or "touch to focus" - indicating an
    interesting area of the viewfinder for the hardware to attempt
    to focus on.

    \snippet multimedia-snippets/camera.cpp Camera custom focus

    The \l minimumZoomFactor() and \l maximumZoomFactor() methods allows checking the
    range of allowed zoom factors. The \l zoomTo() method allows changing the zoom factor.

    \snippet multimedia-snippets/camera.cpp Camera zoom

    See the \l{Camera Overview}{camera overview} for more information.
*/

void QCameraPrivate::_q_error(int error, const QString &errorString)
{
    Q_Q(QCamera);

    this->error = QCamera::Error(error);
    this->errorString = errorString;

    emit q->errorChanged();
    emit q->errorOccurred(this->error, errorString);
}

void QCameraPrivate::init()
{
    Q_Q(QCamera);

    control = QPlatformMediaIntegration::instance()->createCamera(q);
    if (!control) {
        _q_error(QCamera::CameraError, QString::fromUtf8("Camera not supported"));
        return;
    }

    if (cameraInfo.isNull())
        _q_error(QCamera::CameraError, QString::fromUtf8("Invalid camera specified"));
    control->setCamera(cameraInfo);
    q->connect(control, SIGNAL(activeChanged(bool)), q, SIGNAL(activeChanged(bool)));
    q->connect(control, SIGNAL(error(int,QString)), q, SLOT(_q_error(int,QString)));
    cameraExposure = new QCameraExposure(q, control);

    focusControl = control->focusControl();

    if (focusControl) {
        q->connect(focusControl, SIGNAL(minimumZoomFactorChanged(float)),
                   q, SIGNAL(minimumZoomFactorChanged(float)));
        q->connect(focusControl, SIGNAL(maximumZoomFactorChanged(float)),
                   q, SIGNAL(maximumZoomFactorChanged(float)));
    }

    imageProcessing = new QCameraImageProcessing(q, control);
}

/*!
    Construct a QCamera with a \a parent.

    Selects the default camera on the system if more than one camera is available.
*/

QCamera::QCamera(QObject *parent)
    : QCamera(QMediaDevices::defaultVideoInput(), parent)
{
}

/*!
    \since 5.3

    Construct a QCamera from a camera description \a cameraInfo and \a parent.
*/

QCamera::QCamera(const QCameraInfo &cameraInfo, QObject *parent)
    : QObject(*new QCameraPrivate, parent)
{
    Q_D(QCamera);

    d->cameraInfo = cameraInfo;
    d->init();
    setCameraInfo(cameraInfo);
}

/*!
    \since 5.3

    Construct a QCamera which uses a hardware camera located a the specified \a position.

    For example on a mobile phone it can be used to easily choose between front-facing and
    back-facing cameras.

    If no camera is available at the specified \a position or if \a position is
    QCameraInfo::UnspecifiedPosition, the default camera is used.
*/

QCamera::QCamera(QCameraInfo::Position position, QObject *parent)
    : QObject(*new QCameraPrivate, parent)
{
    Q_D(QCamera);

    QCameraInfo info;
    auto cameras = QMediaDevices::videoInputs();
    for (const auto &c : cameras) {
        if (c.position() == position) {
            info = c;
            break;
        }
    }
    if (info.isNull())
        info = QMediaDevices::defaultVideoInput();
    d->cameraInfo = info;
    d->init();
}

/*!
    Destroys the camera object.
*/

QCamera::~QCamera()
{
    Q_D(QCamera);
    if (d->captureSession) {
        d->captureInterface->setCamera(nullptr);
        d->captureSession->setCamera(nullptr);
    }
    Q_ASSERT(!d->captureSession);
}

/*!
    Returns true if the camera can be used.
*/
bool QCamera::isAvailable() const
{
    Q_D(const QCamera);
    return d->control && !d->cameraInfo.isNull();
}

/*!
    Returns true if the camera is currently active.
*/
bool QCamera::isActive() const
{
    Q_D(const QCamera);
    return d->control && d->control->isActive();
}

/*!
    Turns the camera on or off.
*/
void QCamera::setActive(bool active)
{
    Q_D(const QCamera);
    if (d->control)
        d->control->setActive(active);
}

/*!
    Returns the camera exposure control object.
*/
QCameraExposure *QCamera::exposure() const
{
    return d_func()->cameraExposure;
}

/*!
    Returns the camera image processing control object.
*/
QCameraImageProcessing *QCamera::imageProcessing() const
{
    return d_func()->imageProcessing;
}

/*!
    Returns the error state of the object.
*/

QCamera::Error QCamera::error() const
{
    return d_func()->error;
}

/*!
    Returns a human readable string describing a camera's error state.
*/
QString QCamera::errorString() const
{
    return d_func()->errorString;
}

/*! \fn void QCamera::start()

    Starts the camera.

    Same as setActive(true).

    If the camera can't be started for some reason, the errorOccurred() signal is emitted.

    While the camera state is changed to QCamera::ActiveState,
    starting the camera service can be asynchronous with the actual
    status reported with QCamera::status property.
*/

/*! \fn void QCamera::stop()

    Stops the camera.

    \sa unload(), QCamera::InactiveStatus
*/

/*!
    Returns the current status of the camers.
*/
QCamera::Status QCamera::status() const
{
    if(d_func()->control)
        return (QCamera::Status)d_func()->control->status();

    return QCamera::UnavailableStatus;
}


/*!
    Returns the capture session this camera is connected to, or
    a nullptr if the camera is not connected to a capture session.

    use QMediaCaptureSession::setCamera() to connect the camera to
    a session.
*/
QMediaCaptureSession *QCamera::captureSession() const
{
    Q_D(const QCamera);
    return d->captureSession;
}

/*!
    \internal
*/
void QCamera::setCaptureSession(QMediaCaptureSession *session)
{
    Q_D(QCamera);

    d->captureSession = session;
    d->captureInterface = session ? session->platformSession() : nullptr;
    if (d->captureInterface && d->control)
        d->captureInterface->setCamera(d->control);
}

/*!
    Returns the QCameraInfo object associated with this camera.
 */
QCameraInfo QCamera::cameraInfo() const
{
    Q_D(const QCamera);
    return d->cameraInfo;
}

/*!
    Sets the camera object to use the physical camera described by
    \a cameraInfo.
*/
void QCamera::setCameraInfo(const QCameraInfo &cameraInfo)
{
    Q_D(QCamera);
    if (d->cameraInfo == cameraInfo)
        return;
    d->cameraInfo = cameraInfo;
    if (d->cameraInfo.isNull())
        d->_q_error(QCamera::CameraError, QString::fromUtf8("Invalid camera specified"));
    else
        d->_q_error(QCamera::NoError, QString());
    if (d->control)
        d->control->setCamera(d->cameraInfo);
    emit cameraInfoChanged();
    setCameraFormat({});
}

/*!
    Returns the camera format currently used by the camera.
*/
QCameraFormat QCamera::cameraFormat() const
{
    Q_D(const QCamera);
    return d->cameraFormat;
}

/*!
    Tells the camera to use the format described by \a format. This can be used to define
    as specific resolution and frame rate to be used for recording and image capture.
*/
void QCamera::setCameraFormat(const QCameraFormat &format)
{
    Q_D(QCamera);
    if (!d->control || !d->control->setCameraFormat(format))
        return;

    d->cameraFormat = format;
    emit cameraFormatChanged();
}

/*!
    \enum QCamera::Status

    This enum holds the current status of the camera.

    \value ActiveStatus
           The camera has been started and can produce data.
           The viewfinder displays video frames in active state.
           Depending on backend, changing some camera settings like
           capture mode, codecs or resolution in ActiveState may lead
           to changing the camera status to LoadedStatus and StartingStatus while
           the settings are applied and back to ActiveStatus when the camera is ready.
    \value StartingStatus
           The camera is starting in result of state transition to QCamera::ActiveState.
           The camera service is not ready to capture yet.
    \value StoppingStatus
           The camera is stopping in result of state transition from QCamera::ActiveState
           to QCamera::LoadedState or QCamera::UnloadedState.
    \value InactiveStatus
           The camera is not currently active.
    \value UnavailableStatus
           The camera or camera backend is not available.
*/


/*!
    \property QCamera::status
    \brief The current status of the camera object.
*/

/*!
    \enum QCamera::Error

    This enum holds the last error code.

    \value  NoError      No errors have occurred.
    \value  CameraError  An error has occurred.
*/

/*!
    \fn void QCamera::error(QCamera::Error value)
    \obsolete

    Use errorOccurred() instead.
*/

/*!
    \fn void QCamera::errorOccurred(QCamera::Error value)
    \since 5.15

    Signal emitted when error state changes to \a value.
*/

/*!
    \enum QCameraInfo::Position
    \since 5.3

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

    \value UnspecifiedPosition  The camera position is unspecified or unknown.

    \value BackFace  The 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.

    \value FrontFace  The 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. Viewfinder frames of
    front-facing cameras are mirrored horizontally, so the users can see themselves as looking
    into a mirror. Captured images or videos are not mirrored.

    \sa QCameraInfo::position()
*/

/*!
  \fn QCamera::stateChanged(QCamera::State state)

  Signals the camera \a state has changed.

  Usually the state changes is caused by calling
  load(), unload(), start() and stop(),
  but the state can also be changed change as a result of camera error.
*/

/*!
  \fn QCamera::statusChanged(QCamera::Status status)

  Signals the camera \a status has changed.

*/


/*!
    \property QCamera::focusMode
    \brief the current camera focus mode.

    Sets up different focus modes for the camera. All auto focus modes will focus continuously.
    Locking the focus is possible by setting the focus mode to \l FocusModeManual. This will keep
    the current focus and stop any automatic focusing.

    \sa QCamera::isFocusModeSupported()
*/

QCamera::FocusMode QCamera::focusMode() const
{
    Q_D(const QCamera);
    return d->focusControl ? d->focusControl->focusMode() : QCamera::FocusModeAuto;
}

void QCamera::setFocusMode(QCamera::FocusMode mode)
{
    Q_D(QCamera);
    if (!d->focusControl || d->focusControl->focusMode() == mode)
        return;
    d->focusControl->setFocusMode(mode);
    emit focusModeChanged();
}

/*!
    Returns true if the focus \a mode is supported by camera.
*/

bool QCamera::isFocusModeSupported(FocusMode mode) const
{
    Q_D(const QCamera);
    return d->focusControl ? d->focusControl->isFocusModeSupported(mode) : false;
}

/*!
    Returns the point currently used by the auto focus system to focus onto.
 */
QPointF QCamera::focusPoint() const
{
    Q_D(const QCamera);
    return d->focusControl ? d->focusControl->focusPoint() : QPointF(-1., -1.);

}

/*!
  \property QCamera::customFocusPoint

  This property represents the position of the custom focus point, in relative frame coordinates:
  QPointF(0,0) points to the left top frame point, QPointF(0.5,0.5) points to the frame center.

  The custom focus point property is used only in \c FocusPointCustom focus mode.
 */

QPointF QCamera::customFocusPoint() const
{
    Q_D(const QCamera);
    return d->customFocusPoint;
}

void QCamera::setCustomFocusPoint(const QPointF &point)
{
    Q_D(QCamera);
    if (!d->focusControl || d->customFocusPoint == point)
        return;
    d->customFocusPoint = point;
    d->focusControl->setCustomFocusPoint(point);
    Q_EMIT customFocusPointChanged();
}

bool QCamera::isCustomFocusPointSupported() const
{
    Q_D(const QCamera);
    return d->focusControl ? d->focusControl->isCustomFocusPointSupported() : false;
}

/*!
    \property QCamera::focusDistance

    This property return an approximate focus distance of the camera. The value reported is between 0 and 1, 0 being the closest
    possible focus distance, 1 being as far away as possible. Note that 1 is often, but not always infinity.

    Setting the focus distance will be ignored unless the focus mode is set to \l FocusModeManual.
 */
void QCamera::setFocusDistance(float d)
{
    if (!d_func()->focusControl || focusMode() != FocusModeManual)
        return;
    d_func()->focusControl->setFocusDistance(d);
}

float QCamera::focusDistance() const
{
    if (d_func()->focusControl)
        return d_func()->focusControl->focusDistance();
    return 0.;
}

/*!
    Returns the maximum zoom factor.

    This will be \c 1.0 on cameras that do not support zooming.
*/

float QCamera::maximumZoomFactor() const
{
    Q_D(const QCamera);
    return d->focusControl ? d->focusControl->zoomFactorRange().max : 1.;
}

/*!
    Returns the minimum zoom factor.

    This will be \c 1.0 on cameras that do not support zooming.
*/

float QCamera::minimumZoomFactor() const
{
    Q_D(const QCamera);
    return d->focusControl ? d->focusControl->zoomFactorRange().min : 1.;
}

/*!
  \property QCamera::zoomFactor
  \brief The current zoom factor.
*/
float QCamera::zoomFactor() const
{
    return d_func()->zoomFactor;
}

void QCamera::setZoomFactor(float factor)
{
    zoomTo(factor, 0.);
}

/*!
    Zooms to a zoom factor \a factor using \a rate.

    The rate is specified in powers of two per second. A rate of 1
    would take two seconds to zoom from a zoom factor of 1 to a zoom factor of 4.
 */
void QCamera::zoomTo(float factor, float rate)
{
    Q_ASSERT(rate >= 0.);
    if (rate < 0.)
        rate = 0.;

    Q_D(QCamera);
    if (!d->focusControl)
        return;
    factor = qBound(minimumZoomFactor(), factor, maximumZoomFactor());
    d->zoomFactor = factor;
    d->focusControl->zoomTo(factor, rate);
    emit zoomFactorChanged(factor);
}

/*!
    \enum QCamera::FocusMode

    \value FocusModeAuto        Continuous auto focus mode.
    \value FocusModeAutoNear    Continuous auto focus mode on near objects.
    \value FocusModeAutoFar     Continuous auto focus mode on objects far away.
    \value FocusModeHyperfocal  Focus to hyperfocal distance, with the maximum depth of field achieved.
                                All objects at distances from half of this
                                distance out to infinity will be acceptably sharp.
    \value FocusModeInfinity    Focus strictly to infinity.
    \value FocusModeManual      Manual or fixed focus mode.
*/

/*!
    \fn void QCamera::opticalZoomChanged(qreal value)

    Signal emitted when optical zoom value changes to new \a value.
*/

/*!
    \fn void QCamera::digitalZoomChanged(qreal value)

    Signal emitted when digital zoom value changes to new \a value.
*/

/*!
    \fn void QCamera::maximumOpticalZoomChanged(qreal zoom)

    Signal emitted when the maximum supported optical \a zoom value changed.
*/

/*!
    \fn void QCamera::maximumDigitalZoomChanged(qreal zoom)

    Signal emitted when the maximum supported digital \a zoom value changed.

    The maximum supported zoom value can depend on other camera settings,
    like capture mode or resolution.
*/

QT_END_NAMESPACE

#include "moc_qcamera.cpp"