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A camera problem.

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  • jsulmJ jsulm

    @jenya7 For capturing images view finder should not be needed.
    But you could try to enable it to see whether your camera works at all in Qt.
    What exception do you get?

    J Offline
    J Offline
    jenya7
    wrote on last edited by
    #29

    @jsulm said in A camera problem.:

    @jenya7 For capturing images view finder should not be needed.
    But you could try to enable it to see whether your camera works at all in Qt.
    What exception do you get?

    I get
    The inferior stopped because it received a signal from the operating system.
    Signal name: SIGABRT
    Signal meaning: Aborted

    jsulmJ 1 Reply Last reply
    0
    • J jenya7

      @jsulm said in A camera problem.:

      @jenya7 For capturing images view finder should not be needed.
      But you could try to enable it to see whether your camera works at all in Qt.
      What exception do you get?

      I get
      The inferior stopped because it received a signal from the operating system.
      Signal name: SIGABRT
      Signal meaning: Aborted

      jsulmJ Offline
      jsulmJ Offline
      jsulm
      Lifetime Qt Champion
      wrote on last edited by
      #30

      @jenya7 Please run through debugger and post the stack trace.
      Also, you should post your current code with enabled viewfinder.

      https://forum.qt.io/topic/113070/qt-code-of-conduct

      J 1 Reply Last reply
      0
      • jsulmJ jsulm

        @jenya7 Please run through debugger and post the stack trace.
        Also, you should post your current code with enabled viewfinder.

        J Offline
        J Offline
        jenya7
        wrote on last edited by
        #31

        @jsulm said in A camera problem.:

        @jenya7 Please run through debugger and post the stack trace.
        Also, you should post your current code with enabled viewfinder.

        void Camera::setCamera(const QCameraInfo &cameraInfo)
        {
            m_camera.reset(new QCamera(cameraInfo));
        
            connect(m_camera.data(), &QCamera::stateChanged, this, &Camera::updateCameraState);
            connect(m_camera.data(), QOverload<QCamera::Error>::of(&QCamera::error), this, &Camera::displayCameraError);
        
            m_mediaRecorder.reset(new QMediaRecorder(m_camera.data()));
            connect(m_mediaRecorder.data(), &QMediaRecorder::stateChanged, this, &Camera::updateRecorderState);
        
            m_imageCapture.reset(new QCameraImageCapture(m_camera.data()));
        
            connect(m_mediaRecorder.data(), &QMediaRecorder::durationChanged, this, &Camera::updateRecordTime);
            connect(m_mediaRecorder.data(), QOverload<QMediaRecorder::Error>::of(&QMediaRecorder::error),
                    this, &Camera::displayRecorderError);
        
            m_mediaRecorder->setMetaData(QMediaMetaData::Title, QVariant(QLatin1String("Test Title")));
        
            //connect(ui->exposureCompensation, &QAbstractSlider::valueChanged, this, &Camera::setExposureCompensation);
        
        //here the exception occurs
           QCameraViewfinder *v_finder = new QCameraViewfinder();
            //v_finder->setFixedSize(240, 320);
            //v_finder->show();
            v_finder->setAttribute(Qt::WA_NoSystemBackground);
            m_camera->setViewfinder(v_finder);
        
            updateCameraState(m_camera->state());
            updateLockStatus(m_camera->lockStatus(), QCamera::UserRequest);
            updateRecorderState(m_mediaRecorder->state());
        
            connect(m_imageCapture.data(), &QCameraImageCapture::readyForCaptureChanged, this, &Camera::readyForCapture);
            connect(m_imageCapture.data(), &QCameraImageCapture::imageCaptured, this, &Camera::processCapturedImage);
            connect(m_imageCapture.data(), &QCameraImageCapture::imageSaved, this, &Camera::imageSaved);
            connect(m_imageCapture.data(), QOverload<int, QCameraImageCapture::Error, const QString &>::of(&QCameraImageCapture::error),
                    this, &Camera::displayCaptureError);
        
            connect(m_imageCapture.data(), &QCameraImageCapture::imageAvailable, this, &Camera::ImageAvailable);
        
            connect(m_camera.data(), QOverload<QCamera::LockStatus, QCamera::LockChangeReason>::of(&QCamera::lockStatusChanged),
                    this, &Camera::updateLockStatus);
        
            //ui->captureWidget->setTabEnabled(0, (m_camera->isCaptureModeSupported(QCamera::CaptureStillImage)));
            //ui->captureWidget->setTabEnabled(1, (m_camera->isCaptureModeSupported(QCamera::CaptureVideo)));
        
            updateCaptureMode(0);
            m_camera->start();
        }
        

        and a call stack

        1  __GI_raise                                                  raise.c      50  0xb5830f14 
        2  __GI_abort                                                  abort.c      79  0xb581c230 
        3  QMessageLogger::fatal(const char *, ...) const                               0xb5c1c004 
        4  QWidgetPrivate::QWidgetPrivate(int)                                          0xb698e204 
        5  QWidget::QWidget(QWidget *, QFlags<Qt::WindowType>)                          0xb69ab42c 
        6  QVideoWidget::QVideoWidget(QVideoWidgetPrivate&, QWidget *)                  0xb6f3ed70 
        7  QCameraViewfinder::QCameraViewfinder(QWidget *)                              0xb6f388f4 
        8  Camera::setCamera                                           camera.cpp   148 0x5a000        //this line is focused
        9  Camera::Camera                                              camera.cpp   112 0x599ec    
        10 __static_initialization_and_destruction_0                   camera.cpp   69  0x5bd58    
        11 _GLOBAL__sub_I_camera.cpp(void)                             camera.cpp   544 0x5bdb4    
        12 __libc_csu_init                                                              0xbed54    
        13 __libc_start_main                                           libc-start.c 264 0xb581c6ac 
        14 _start        
        
        jsulmJ 1 Reply Last reply
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        • J jenya7

          @jsulm said in A camera problem.:

          @jenya7 Please run through debugger and post the stack trace.
          Also, you should post your current code with enabled viewfinder.

          void Camera::setCamera(const QCameraInfo &cameraInfo)
          {
              m_camera.reset(new QCamera(cameraInfo));
          
              connect(m_camera.data(), &QCamera::stateChanged, this, &Camera::updateCameraState);
              connect(m_camera.data(), QOverload<QCamera::Error>::of(&QCamera::error), this, &Camera::displayCameraError);
          
              m_mediaRecorder.reset(new QMediaRecorder(m_camera.data()));
              connect(m_mediaRecorder.data(), &QMediaRecorder::stateChanged, this, &Camera::updateRecorderState);
          
              m_imageCapture.reset(new QCameraImageCapture(m_camera.data()));
          
              connect(m_mediaRecorder.data(), &QMediaRecorder::durationChanged, this, &Camera::updateRecordTime);
              connect(m_mediaRecorder.data(), QOverload<QMediaRecorder::Error>::of(&QMediaRecorder::error),
                      this, &Camera::displayRecorderError);
          
              m_mediaRecorder->setMetaData(QMediaMetaData::Title, QVariant(QLatin1String("Test Title")));
          
              //connect(ui->exposureCompensation, &QAbstractSlider::valueChanged, this, &Camera::setExposureCompensation);
          
          //here the exception occurs
             QCameraViewfinder *v_finder = new QCameraViewfinder();
              //v_finder->setFixedSize(240, 320);
              //v_finder->show();
              v_finder->setAttribute(Qt::WA_NoSystemBackground);
              m_camera->setViewfinder(v_finder);
          
              updateCameraState(m_camera->state());
              updateLockStatus(m_camera->lockStatus(), QCamera::UserRequest);
              updateRecorderState(m_mediaRecorder->state());
          
              connect(m_imageCapture.data(), &QCameraImageCapture::readyForCaptureChanged, this, &Camera::readyForCapture);
              connect(m_imageCapture.data(), &QCameraImageCapture::imageCaptured, this, &Camera::processCapturedImage);
              connect(m_imageCapture.data(), &QCameraImageCapture::imageSaved, this, &Camera::imageSaved);
              connect(m_imageCapture.data(), QOverload<int, QCameraImageCapture::Error, const QString &>::of(&QCameraImageCapture::error),
                      this, &Camera::displayCaptureError);
          
              connect(m_imageCapture.data(), &QCameraImageCapture::imageAvailable, this, &Camera::ImageAvailable);
          
              connect(m_camera.data(), QOverload<QCamera::LockStatus, QCamera::LockChangeReason>::of(&QCamera::lockStatusChanged),
                      this, &Camera::updateLockStatus);
          
              //ui->captureWidget->setTabEnabled(0, (m_camera->isCaptureModeSupported(QCamera::CaptureStillImage)));
              //ui->captureWidget->setTabEnabled(1, (m_camera->isCaptureModeSupported(QCamera::CaptureVideo)));
          
              updateCaptureMode(0);
              m_camera->start();
          }
          

          and a call stack

          1  __GI_raise                                                  raise.c      50  0xb5830f14 
          2  __GI_abort                                                  abort.c      79  0xb581c230 
          3  QMessageLogger::fatal(const char *, ...) const                               0xb5c1c004 
          4  QWidgetPrivate::QWidgetPrivate(int)                                          0xb698e204 
          5  QWidget::QWidget(QWidget *, QFlags<Qt::WindowType>)                          0xb69ab42c 
          6  QVideoWidget::QVideoWidget(QVideoWidgetPrivate&, QWidget *)                  0xb6f3ed70 
          7  QCameraViewfinder::QCameraViewfinder(QWidget *)                              0xb6f388f4 
          8  Camera::setCamera                                           camera.cpp   148 0x5a000        //this line is focused
          9  Camera::Camera                                              camera.cpp   112 0x599ec    
          10 __static_initialization_and_destruction_0                   camera.cpp   69  0x5bd58    
          11 _GLOBAL__sub_I_camera.cpp(void)                             camera.cpp   544 0x5bdb4    
          12 __libc_csu_init                                                              0xbed54    
          13 __libc_start_main                                           libc-start.c 264 0xb581c6ac 
          14 _start        
          
          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #32

          @jenya7 I'm confused by the code you posted: sometimes you use m_camera. and sometimes m_camera->! How can this even compile?!

          Try to set a parent on QCameraViewfinder to see whether it makes a difference.

          https://forum.qt.io/topic/113070/qt-code-of-conduct

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          • jsulmJ jsulm

            @jenya7 I'm confused by the code you posted: sometimes you use m_camera. and sometimes m_camera->! How can this even compile?!

            Try to set a parent on QCameraViewfinder to see whether it makes a difference.

            J Offline
            J Offline
            jenya7
            wrote on last edited by jenya7
            #33

            @jsulm said in A camera problem.:

            @jenya7 I'm confused by the code you posted: sometimes you use m_camera. and sometimes m_camera->! How can this even compile?!

            Try to set a parent on QCameraViewfinder to see whether it makes a difference.

            Hmm..It's an example from the official Qt/Examples folder. I guess those with a dot - the intrinsic methods, not from a Camera class.

            for example - m_camera.reset
            from - C:\Qt\5.12.0\mingw73_64\include\QtCore\qscopedpointer.h

            jsulmJ 1 Reply Last reply
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            • J jenya7

              @jsulm said in A camera problem.:

              @jenya7 I'm confused by the code you posted: sometimes you use m_camera. and sometimes m_camera->! How can this even compile?!

              Try to set a parent on QCameraViewfinder to see whether it makes a difference.

              Hmm..It's an example from the official Qt/Examples folder. I guess those with a dot - the intrinsic methods, not from a Camera class.

              for example - m_camera.reset
              from - C:\Qt\5.12.0\mingw73_64\include\QtCore\qscopedpointer.h

              jsulmJ Offline
              jsulmJ Offline
              jsulm
              Lifetime Qt Champion
              wrote on last edited by
              #34

              @jenya7 No, this belongs to C++ basics: if m_camera is a pointer then you have to use -> if it is not a pointer then you have to use dot. So, what is m_camera in YOUR code?

              https://forum.qt.io/topic/113070/qt-code-of-conduct

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              • jsulmJ jsulm

                @jenya7 No, this belongs to C++ basics: if m_camera is a pointer then you have to use -> if it is not a pointer then you have to use dot. So, what is m_camera in YOUR code?

                J Offline
                J Offline
                jenya7
                wrote on last edited by jenya7
                #35

                @jsulm said in A camera problem.:

                @jenya7 No, this belongs to C++ basics: if m_camera is a pointer then you have to use -> if it is not a pointer then you have to use dot. So, what is m_camera in YOUR code?

                in camera.h

                class Camera : public QMainWindow
                {
                    Q_OBJECT
                
                public:
                    Camera(QObject *parent = nullptr);
                
                     void takeImage();
                
                private slots:
                    void setCamera(const QCameraInfo &cameraInfo);
                
                    void startCamera();
                    void stopCamera();
                
                    void record();
                    void pause();
                    void stop();
                    void setMuted(bool);
                
                    void toggleLock();
                    void displayCaptureError(int, QCameraImageCapture::Error, const QString &errorString);
                
                    void configureCaptureSettings();
                    void configureVideoSettings();
                    void configureImageSettings();
                    void displayRecorderError();
                    void displayCameraError();
                
                    void updateCameraDevice(QAction *action);
                
                    void updateCameraState(QCamera::State);
                    void updateCaptureMode();
                    void updateRecorderState(QMediaRecorder::State state);
                    void setExposureCompensation(int index);
                
                    void updateRecordTime();
                
                    void processCapturedImage(int requestId, const QImage &img);
                    void updateLockStatus(QCamera::LockStatus, QCamera::LockChangeReason);
                
                    void displayViewfinder();
                    void displayCapturedImage();
                
                    void readyForCapture(bool ready);
                    void imageSaved(int id, const QString &fileName);
                
                protected:
                    void keyPressEvent(QKeyEvent *event) override;
                    void keyReleaseEvent(QKeyEvent *event) override;
                    void closeEvent(QCloseEvent *event) override;
                
                private:
                    Ui::Camera *ui;
                
                    QScopedPointer<QCamera> m_camera;
                
                    QScopedPointer<QCameraImageCapture> m_imageCapture;
                    QScopedPointer<QMediaRecorder> m_mediaRecorder;
                
                    QImageEncoderSettings m_imageSettings;
                    QAudioEncoderSettings m_audioSettings;
                    QVideoEncoderSettings m_videoSettings;
                    QString m_videoContainerFormat;
                    bool m_isCapturingImage = false;
                    bool m_applicationExiting = false;
                };
                
                

                It's a private member initialized after the camera found in a constructor.

                Camera::Camera(QObject *parent) : QObject(parent) 
                {
                      //some code
                      if (cameraInfo == QCameraInfo::defaultCamera())
                              videoDeviceAction->setChecked(true);
                
                       setCamera(QCameraInfo::defaultCamera());
                }
                
                jsulmJ 1 Reply Last reply
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                • J jenya7

                  @jsulm said in A camera problem.:

                  @jenya7 No, this belongs to C++ basics: if m_camera is a pointer then you have to use -> if it is not a pointer then you have to use dot. So, what is m_camera in YOUR code?

                  in camera.h

                  class Camera : public QMainWindow
                  {
                      Q_OBJECT
                  
                  public:
                      Camera(QObject *parent = nullptr);
                  
                       void takeImage();
                  
                  private slots:
                      void setCamera(const QCameraInfo &cameraInfo);
                  
                      void startCamera();
                      void stopCamera();
                  
                      void record();
                      void pause();
                      void stop();
                      void setMuted(bool);
                  
                      void toggleLock();
                      void displayCaptureError(int, QCameraImageCapture::Error, const QString &errorString);
                  
                      void configureCaptureSettings();
                      void configureVideoSettings();
                      void configureImageSettings();
                      void displayRecorderError();
                      void displayCameraError();
                  
                      void updateCameraDevice(QAction *action);
                  
                      void updateCameraState(QCamera::State);
                      void updateCaptureMode();
                      void updateRecorderState(QMediaRecorder::State state);
                      void setExposureCompensation(int index);
                  
                      void updateRecordTime();
                  
                      void processCapturedImage(int requestId, const QImage &img);
                      void updateLockStatus(QCamera::LockStatus, QCamera::LockChangeReason);
                  
                      void displayViewfinder();
                      void displayCapturedImage();
                  
                      void readyForCapture(bool ready);
                      void imageSaved(int id, const QString &fileName);
                  
                  protected:
                      void keyPressEvent(QKeyEvent *event) override;
                      void keyReleaseEvent(QKeyEvent *event) override;
                      void closeEvent(QCloseEvent *event) override;
                  
                  private:
                      Ui::Camera *ui;
                  
                      QScopedPointer<QCamera> m_camera;
                  
                      QScopedPointer<QCameraImageCapture> m_imageCapture;
                      QScopedPointer<QMediaRecorder> m_mediaRecorder;
                  
                      QImageEncoderSettings m_imageSettings;
                      QAudioEncoderSettings m_audioSettings;
                      QVideoEncoderSettings m_videoSettings;
                      QString m_videoContainerFormat;
                      bool m_isCapturingImage = false;
                      bool m_applicationExiting = false;
                  };
                  
                  

                  It's a private member initialized after the camera found in a constructor.

                  Camera::Camera(QObject *parent) : QObject(parent) 
                  {
                        //some code
                        if (cameraInfo == QCameraInfo::defaultCamera())
                                videoDeviceAction->setChecked(true);
                  
                         setCamera(QCameraInfo::defaultCamera());
                  }
                  
                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #36

                  @jenya7 OK, now it makes sense. Did you try to set parent on the viewfinder?

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                  J 1 Reply Last reply
                  0
                  • jsulmJ jsulm

                    @jenya7 OK, now it makes sense. Did you try to set parent on the viewfinder?

                    J Offline
                    J Offline
                    jenya7
                    wrote on last edited by
                    #37

                    @jsulm said in A camera problem.:

                    @jenya7 OK, now it makes sense. Did you try to set parent on the viewfinder?

                    That's it - they use the widget int the app. What should I choose as a parent?

                    jsulmJ 1 Reply Last reply
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                    • J jenya7

                      @jsulm said in A camera problem.:

                      @jenya7 OK, now it makes sense. Did you try to set parent on the viewfinder?

                      That's it - they use the widget int the app. What should I choose as a parent?

                      jsulmJ Offline
                      jsulmJ Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on last edited by
                      #38

                      @jenya7 Do you have any other UI/widgets in your application?

                      https://forum.qt.io/topic/113070/qt-code-of-conduct

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                      • jsulmJ jsulm

                        @jenya7 Do you have any other UI/widgets in your application?

                        J Offline
                        J Offline
                        jenya7
                        wrote on last edited by jenya7
                        #39

                        @jsulm said in A camera problem.:

                        @jenya7 Do you have any other UI/widgets in your application?

                        well...I can put one just for debug sake. right now it's a window with a text box for a command line receiving.

                        I did so

                        QWidget *viewfinderPage;
                        viewfinderPage = new QWidget();
                        v_finder = new QCameraViewfinder(viewfinderPage);
                        

                        and I get the same exception on
                        viewfinderPage = new QWidget();

                        jsulmJ 1 Reply Last reply
                        0
                        • J jenya7

                          @jsulm said in A camera problem.:

                          @jenya7 Do you have any other UI/widgets in your application?

                          well...I can put one just for debug sake. right now it's a window with a text box for a command line receiving.

                          I did so

                          QWidget *viewfinderPage;
                          viewfinderPage = new QWidget();
                          v_finder = new QCameraViewfinder(viewfinderPage);
                          

                          and I get the same exception on
                          viewfinderPage = new QWidget();

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #40

                          @jenya7 said in A camera problem.:

                          and I get the same exception on
                          viewfinderPage = new QWidget();

                          You get same crash if you instanciate a QWidget?
                          Then something is really broken in your setup.
                          Can you build and execute a simple Qt widget application?

                          https://forum.qt.io/topic/113070/qt-code-of-conduct

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                          • jsulmJ jsulm

                            @jenya7 said in A camera problem.:

                            and I get the same exception on
                            viewfinderPage = new QWidget();

                            You get same crash if you instanciate a QWidget?
                            Then something is really broken in your setup.
                            Can you build and execute a simple Qt widget application?

                            J Offline
                            J Offline
                            jenya7
                            wrote on last edited by
                            #41

                            @jsulm said in A camera problem.:

                            @jenya7 said in A camera problem.:

                            and I get the same exception on
                            viewfinderPage = new QWidget();

                            You get same crash if you instanciate a QWidget?
                            Then something is really broken in your setup.
                            Can you build and execute a simple Qt widget application?

                            actually viewfinderPage is null pointed. I have to create it. I'll try.

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                            • J Offline
                              J Offline
                              jenya7
                              wrote on last edited by jenya7
                              #42

                              well...I added in a main window

                              QCameraViewfinder *m_viewfinder =  new QCameraViewfinder(this);
                              
                              

                              and then in camera class

                              camera->setViewfinder(m_viewfinder );
                              

                              But still get the message - "Image Capture Error: Camera not ready"
                              I get it on
                              m_imageCapture->capture();
                              When I try to go into capture() - I can't - the source unavailable, can not debug it to see why m_imageCapture decides the camera isn't ready.

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                              • B Offline
                                B Offline
                                Bonnie
                                wrote on last edited by
                                #43

                                According to https://doc.qt.io/qt-5/qcamera.html#State-enum :

                                In the active state as soon as camera is started the viewfinder displays video frames and the camera is ready for capture.
                                

                                So capture should not be called right after start.
                                After calling start, you should asynchronously wait until the state turns to Active before performing any capturing.

                                J 1 Reply Last reply
                                3
                                • B Bonnie

                                  According to https://doc.qt.io/qt-5/qcamera.html#State-enum :

                                  In the active state as soon as camera is started the viewfinder displays video frames and the camera is ready for capture.
                                  

                                  So capture should not be called right after start.
                                  After calling start, you should asynchronously wait until the state turns to Active before performing any capturing.

                                  J Offline
                                  J Offline
                                  jenya7
                                  wrote on last edited by jenya7
                                  #44

                                  @Bonnie said in A camera problem.:

                                  According to https://doc.qt.io/qt-5/qcamera.html#State-enum :

                                  In the active state as soon as camera is started the viewfinder displays video frames and the camera is ready for capture.
                                  

                                  So capture should not be called right after start.
                                  After calling start, you should asynchronously wait until the state turns to Active before performing any capturing.

                                  so I did

                                  void Camera::takeImage()
                                  {
                                      m_camera->start();
                                      m_camera->searchAndLock();
                                  
                                       while (m_imageCapture->isReadyForCapture() == false) ;
                                  
                                      m_isCapturingImage = true;
                                      m_imageCapture->capture();
                                  
                                      m_camera->unlock();
                                  }
                                  
                                  

                                  it's never ready. never gets out of while.

                                  1 Reply Last reply
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                                  • SGaistS Offline
                                    SGaistS Offline
                                    SGaist
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #45

                                    Hi,

                                    Your tight loop does not allow Qt's event loop to run. You should either use an event loop to "block" the execution or properly implement this through signals and slots.

                                    Interested in AI ? www.idiap.ch
                                    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                    J 1 Reply Last reply
                                    2
                                    • SGaistS SGaist

                                      Hi,

                                      Your tight loop does not allow Qt's event loop to run. You should either use an event loop to "block" the execution or properly implement this through signals and slots.

                                      J Offline
                                      J Offline
                                      jenya7
                                      wrote on last edited by
                                      #46

                                      @SGaist said in A camera problem.:

                                      Hi,

                                      Your tight loop does not allow Qt's event loop to run. You should either use an event loop to "block" the execution or properly implement this through signals and slots.

                                      OK. Did so

                                      connect(m_imageCapture.data(), &QCameraImageCapture::isReadyForCapture, this, &Camera::IsReadyForCapture);
                                      
                                      void Camera::takeImage()
                                      {
                                          m_camera->start();
                                          m_camera->searchAndLock();
                                      
                                         // while (m_imageCapture->isReadyForCapture() == false) ;
                                      
                                          //m_isCapturingImage = true;
                                          //m_imageCapture->capture();
                                      
                                          //m_camera->unlock();
                                      }
                                      
                                      void Camera::IsReadyForCapture()
                                      {
                                          m_isCapturingImage = true;
                                          m_imageCapture->capture();
                                      
                                          m_camera->unlock();
                                      }
                                      

                                      It never happens.

                                      JonBJ 1 Reply Last reply
                                      0
                                      • J jenya7

                                        @SGaist said in A camera problem.:

                                        Hi,

                                        Your tight loop does not allow Qt's event loop to run. You should either use an event loop to "block" the execution or properly implement this through signals and slots.

                                        OK. Did so

                                        connect(m_imageCapture.data(), &QCameraImageCapture::isReadyForCapture, this, &Camera::IsReadyForCapture);
                                        
                                        void Camera::takeImage()
                                        {
                                            m_camera->start();
                                            m_camera->searchAndLock();
                                        
                                           // while (m_imageCapture->isReadyForCapture() == false) ;
                                        
                                            //m_isCapturingImage = true;
                                            //m_imageCapture->capture();
                                        
                                            //m_camera->unlock();
                                        }
                                        
                                        void Camera::IsReadyForCapture()
                                        {
                                            m_isCapturingImage = true;
                                            m_imageCapture->capture();
                                        
                                            m_camera->unlock();
                                        }
                                        

                                        It never happens.

                                        JonBJ Offline
                                        JonBJ Offline
                                        JonB
                                        wrote on last edited by
                                        #47

                                        @jenya7 said in A camera problem.:

                                        connect(m_imageCapture.data(), &QCameraImageCapture::isReadyForCapture, this, &Camera::IsReadyForCapture);

                                        Did this go through without complaint? I am "surprised", as QCameraImageCapture::isReadyForCapture() is not a signal, would have thought connect() would barf on that.... Try using void QCameraImageCapture::readyForCaptureChanged(bool ready) signal?

                                        J 1 Reply Last reply
                                        2
                                        • JonBJ JonB

                                          @jenya7 said in A camera problem.:

                                          connect(m_imageCapture.data(), &QCameraImageCapture::isReadyForCapture, this, &Camera::IsReadyForCapture);

                                          Did this go through without complaint? I am "surprised", as QCameraImageCapture::isReadyForCapture() is not a signal, would have thought connect() would barf on that.... Try using void QCameraImageCapture::readyForCaptureChanged(bool ready) signal?

                                          J Offline
                                          J Offline
                                          jenya7
                                          wrote on last edited by
                                          #48

                                          @JonB said in A camera problem.:

                                          @jenya7 said in A camera problem.:

                                          connect(m_imageCapture.data(), &QCameraImageCapture::isReadyForCapture, this, &Camera::IsReadyForCapture);

                                          Did this go through without complaint? I am "surprised", as QCameraImageCapture::isReadyForCapture() is not a signal, would have thought connect() would barf on that.... Try using void QCameraImageCapture::readyForCaptureChanged(bool ready) signal?

                                          did so

                                          connect(m_imageCapture.data(), &QCameraImageCapture::readyForCaptureChanged, this, &Camera::ReadyForCaptureChanged);
                                          
                                          void Camera::takeImage()
                                          {
                                              m_camera->start();
                                              m_camera->searchAndLock();
                                          }
                                          
                                          void Camera::ReadyForCaptureChanged(bool ready)
                                          {
                                              m_isCapturingImage = true;
                                              m_imageCapture->capture();
                                          
                                              m_camera->unlock();
                                          }
                                          

                                          never get into ReadyForCaptureChanged

                                          jsulmJ 1 Reply Last reply
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