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A camera problem.

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  • J jenya7

    @jsulm said in A camera problem.:

    @jenya7 said in A camera problem.:

    never get into ReadyForCaptureChanged

    Sure? How did you verify that?

    I set a break point inside. I see it goes into takeImage but never gets to ReadyForCaptureChanged
    Now I don't get any errors but it prints
    Starting camera without viewfinder available
    Is it OK?

    JonBJ Online
    JonBJ Online
    JonB
    wrote on last edited by
    #52

    @jenya7
    Just to make sure, what happens in your code after you call your takeImage()? Do you allow the main event loop to run, or do you have other code which does not?

    J 1 Reply Last reply
    0
    • J.HilkJ J.Hilk

      @jenya7
      maybe its a typical object lifetime problem.

      where does your Camera instance exist/live ?

      J Offline
      J Offline
      jenya7
      wrote on last edited by
      #53

      @J-Hilk said in A camera problem.:

      @jenya7
      maybe its a typical object lifetime problem.

      where does your Camera instance exist/live ?

      It's a global object. I call it's methods from a command line parser object.

      J.HilkJ 1 Reply Last reply
      0
      • J jenya7

        @J-Hilk said in A camera problem.:

        @jenya7
        maybe its a typical object lifetime problem.

        where does your Camera instance exist/live ?

        It's a global object. I call it's methods from a command line parser object.

        J.HilkJ Offline
        J.HilkJ Offline
        J.Hilk
        Moderators
        wrote on last edited by
        #54

        @jenya7 soooo, inside main() ?


        Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


        Q: What's that?
        A: It's blue light.
        Q: What does it do?
        A: It turns blue.

        J 1 Reply Last reply
        0
        • JonBJ JonB

          @jenya7
          Just to make sure, what happens in your code after you call your takeImage()? Do you allow the main event loop to run, or do you have other code which does not?

          J Offline
          J Offline
          jenya7
          wrote on last edited by
          #55

          @JonB said in A camera problem.:

          @jenya7
          Just to make sure, what happens in your code after you call your takeImage()? Do you allow the main event loop to run, or do you have other code which does not?

          well..I guess it's running, cause my command lines parser reacts and process my commands.

          1 Reply Last reply
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          • J.HilkJ J.Hilk

            @jenya7 soooo, inside main() ?

            J Offline
            J Offline
            jenya7
            wrote on last edited by
            #56

            @J-Hilk said in A camera problem.:

            @jenya7 soooo, inside main() ?

            actually for debug purposes I instantiated it in other module - command line parser, but it's static and never goes out of scope.

            J.HilkJ 1 Reply Last reply
            0
            • J jenya7

              @J-Hilk said in A camera problem.:

              @jenya7 soooo, inside main() ?

              actually for debug purposes I instantiated it in other module - command line parser, but it's static and never goes out of scope.

              J.HilkJ Offline
              J.HilkJ Offline
              J.Hilk
              Moderators
              wrote on last edited by
              #57

              @jenya7

              static

              thats actually forbidden, no QObject based object must be created before the QCoreApplication instance. Static objects will be created before the QCoreApplication instance.


              Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


              Q: What's that?
              A: It's blue light.
              Q: What does it do?
              A: It turns blue.

              J 1 Reply Last reply
              0
              • J.HilkJ J.Hilk

                @jenya7

                static

                thats actually forbidden, no QObject based object must be created before the QCoreApplication instance. Static objects will be created before the QCoreApplication instance.

                J Offline
                J Offline
                jenya7
                wrote on last edited by
                #58

                @J-Hilk said in A camera problem.:

                @jenya7

                static

                thats actually forbidden, no QObject based object must be created before the QCoreApplication instance. Static objects will be created before the QCoreApplication instance.

                I mean it it's created without static attribute, but i's not locally allocated.

                J 1 Reply Last reply
                0
                • J jenya7

                  @J-Hilk said in A camera problem.:

                  @jenya7

                  static

                  thats actually forbidden, no QObject based object must be created before the QCoreApplication instance. Static objects will be created before the QCoreApplication instance.

                  I mean it it's created without static attribute, but i's not locally allocated.

                  J Offline
                  J Offline
                  jenya7
                  wrote on last edited by
                  #59

                  If I only could drill down to the cause of
                  "Image Capture Error: Camera not ready"
                  What makes it not ready for m_imageCapture...

                  JonBJ 1 Reply Last reply
                  0
                  • J jenya7

                    If I only could drill down to the cause of
                    "Image Capture Error: Camera not ready"
                    What makes it not ready for m_imageCapture...

                    JonBJ Online
                    JonBJ Online
                    JonB
                    wrote on last edited by
                    #60

                    @jenya7
                    I know nothing about cameras and captures, so no idea about causes. I will say your definition of void Camera::ReadyForCaptureChanged(bool ready) is wrong, since it does not examine the ready parameter value. But if you say it's never hit that is moot.

                    J 1 Reply Last reply
                    0
                    • JonBJ JonB

                      @jenya7
                      I know nothing about cameras and captures, so no idea about causes. I will say your definition of void Camera::ReadyForCaptureChanged(bool ready) is wrong, since it does not examine the ready parameter value. But if you say it's never hit that is moot.

                      J Offline
                      J Offline
                      jenya7
                      wrote on last edited by
                      #61

                      @JonB said in A camera problem.:

                      @jenya7
                      I know nothing about cameras and captures, so no idea about causes. I will say your definition of void Camera::ReadyForCaptureChanged(bool ready) is wrong, since it does not examine the ready parameter value. But if you say it's never hit that is moot.

                      Yes. But it never hits if (ready) line.

                      void Camera::ReadyForCaptureChanged(bool ready)
                      {
                          if (ready)
                          {
                              m_isCapturingImage = true;
                              m_imageCapture->capture();
                      
                              m_camera->unlock();
                          }
                      }
                      
                      J.HilkJ JonBJ 2 Replies Last reply
                      0
                      • J jenya7

                        @JonB said in A camera problem.:

                        @jenya7
                        I know nothing about cameras and captures, so no idea about causes. I will say your definition of void Camera::ReadyForCaptureChanged(bool ready) is wrong, since it does not examine the ready parameter value. But if you say it's never hit that is moot.

                        Yes. But it never hits if (ready) line.

                        void Camera::ReadyForCaptureChanged(bool ready)
                        {
                            if (ready)
                            {
                                m_isCapturingImage = true;
                                m_imageCapture->capture();
                        
                                m_camera->unlock();
                            }
                        }
                        
                        J.HilkJ Offline
                        J.HilkJ Offline
                        J.Hilk
                        Moderators
                        wrote on last edited by
                        #62

                        @jenya7
                        do you call show() on your viewfinder instance ? It will probably never change its state, if the viewfinder is not "visible"


                        Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                        Q: What's that?
                        A: It's blue light.
                        Q: What does it do?
                        A: It turns blue.

                        J 1 Reply Last reply
                        0
                        • J jenya7

                          @JonB said in A camera problem.:

                          @jenya7
                          I know nothing about cameras and captures, so no idea about causes. I will say your definition of void Camera::ReadyForCaptureChanged(bool ready) is wrong, since it does not examine the ready parameter value. But if you say it's never hit that is moot.

                          Yes. But it never hits if (ready) line.

                          void Camera::ReadyForCaptureChanged(bool ready)
                          {
                              if (ready)
                              {
                                  m_isCapturingImage = true;
                                  m_imageCapture->capture();
                          
                                  m_camera->unlock();
                              }
                          }
                          
                          JonBJ Online
                          JonBJ Online
                          JonB
                          wrote on last edited by
                          #63

                          @jenya7
                          Yes, at least the code is right, but won't help if that never gets hit.
                          Bearing in mind I know nothing about cameras, why did you comment out the m_camera->isCaptureModeSupported(...) lines, what do these actually return? If they return false presumably that would explain why you never get QCameraImageCapture::readyForCaptureChanged ?

                          Oh I see @J-Hilk has chimed in with some knowledge of this camera stuff....

                          1 Reply Last reply
                          0
                          • J.HilkJ J.Hilk

                            @jenya7
                            do you call show() on your viewfinder instance ? It will probably never change its state, if the viewfinder is not "visible"

                            J Offline
                            J Offline
                            jenya7
                            wrote on last edited by jenya7
                            #64

                            @J-Hilk said in A camera problem.:

                            @jenya7
                            do you call show() on your viewfinder instance ? It will probably never change its state, if the viewfinder is not "visible"

                            It can be an issue.
                            Although I create an object in mainwindow.cpp

                            QCameraViewfinder *v_finder;
                            
                            MainWindow::MainWindow(QWidget *parent) :
                                QMainWindow(parent),
                                ui(new Ui::MainWindow)
                            {
                                v_finder= new QCameraViewfinder(this);
                            
                                ui->setupUi(this);
                                ui->textEditTerminalTx->installEventFilter(this);
                            }
                            

                            It's not physically allocated. The app wasn't suppose to have such widget.
                            So on v_finder->show() I get an exception.
                            Is it possible to emulate the viewfinder ?

                            J jsulmJ JonBJ 3 Replies Last reply
                            0
                            • J jenya7

                              @J-Hilk said in A camera problem.:

                              @jenya7
                              do you call show() on your viewfinder instance ? It will probably never change its state, if the viewfinder is not "visible"

                              It can be an issue.
                              Although I create an object in mainwindow.cpp

                              QCameraViewfinder *v_finder;
                              
                              MainWindow::MainWindow(QWidget *parent) :
                                  QMainWindow(parent),
                                  ui(new Ui::MainWindow)
                              {
                                  v_finder= new QCameraViewfinder(this);
                              
                                  ui->setupUi(this);
                                  ui->textEditTerminalTx->installEventFilter(this);
                              }
                              

                              It's not physically allocated. The app wasn't suppose to have such widget.
                              So on v_finder->show() I get an exception.
                              Is it possible to emulate the viewfinder ?

                              J Offline
                              J Offline
                              jenya7
                              wrote on last edited by
                              #65
                              This post is deleted!
                              1 Reply Last reply
                              0
                              • J jenya7

                                @J-Hilk said in A camera problem.:

                                @jenya7
                                do you call show() on your viewfinder instance ? It will probably never change its state, if the viewfinder is not "visible"

                                It can be an issue.
                                Although I create an object in mainwindow.cpp

                                QCameraViewfinder *v_finder;
                                
                                MainWindow::MainWindow(QWidget *parent) :
                                    QMainWindow(parent),
                                    ui(new Ui::MainWindow)
                                {
                                    v_finder= new QCameraViewfinder(this);
                                
                                    ui->setupUi(this);
                                    ui->textEditTerminalTx->installEventFilter(this);
                                }
                                

                                It's not physically allocated. The app wasn't suppose to have such widget.
                                So on v_finder->show() I get an exception.
                                Is it possible to emulate the viewfinder ?

                                jsulmJ Offline
                                jsulmJ Offline
                                jsulm
                                Lifetime Qt Champion
                                wrote on last edited by
                                #66

                                @jenya7 said in A camera problem.:

                                It's not physically allocated

                                It is, see the first line in the constructor

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

                                J 1 Reply Last reply
                                0
                                • J jenya7

                                  @J-Hilk said in A camera problem.:

                                  @jenya7
                                  do you call show() on your viewfinder instance ? It will probably never change its state, if the viewfinder is not "visible"

                                  It can be an issue.
                                  Although I create an object in mainwindow.cpp

                                  QCameraViewfinder *v_finder;
                                  
                                  MainWindow::MainWindow(QWidget *parent) :
                                      QMainWindow(parent),
                                      ui(new Ui::MainWindow)
                                  {
                                      v_finder= new QCameraViewfinder(this);
                                  
                                      ui->setupUi(this);
                                      ui->textEditTerminalTx->installEventFilter(this);
                                  }
                                  

                                  It's not physically allocated. The app wasn't suppose to have such widget.
                                  So on v_finder->show() I get an exception.
                                  Is it possible to emulate the viewfinder ?

                                  JonBJ Online
                                  JonBJ Online
                                  JonB
                                  wrote on last edited by
                                  #67

                                  @jenya7
                                  What is "not physically allocated", and why do you get an exception on what?

                                  There is a basic example at https://doc.qt.io/qt-5/qcameraviewfinder.html

                                  camera = new QCamera;
                                  
                                  viewfinder = new QCameraViewfinder();
                                  viewfinder->show();
                                  
                                  camera->setViewfinder(viewfinder);
                                  
                                  imageCapture = new QCameraImageCapture(camera);
                                  
                                  camera->setCaptureMode(QCamera::CaptureStillImage);
                                  camera->start();
                                  

                                  Did you test whether just this code might work for you?

                                  You also ought check those m_camera->isCaptureModeSupported(...) I mentioned, else you are whistling in the wind....

                                  J 2 Replies Last reply
                                  1
                                  • JonBJ JonB

                                    @jenya7
                                    What is "not physically allocated", and why do you get an exception on what?

                                    There is a basic example at https://doc.qt.io/qt-5/qcameraviewfinder.html

                                    camera = new QCamera;
                                    
                                    viewfinder = new QCameraViewfinder();
                                    viewfinder->show();
                                    
                                    camera->setViewfinder(viewfinder);
                                    
                                    imageCapture = new QCameraImageCapture(camera);
                                    
                                    camera->setCaptureMode(QCamera::CaptureStillImage);
                                    camera->start();
                                    

                                    Did you test whether just this code might work for you?

                                    You also ought check those m_camera->isCaptureModeSupported(...) I mentioned, else you are whistling in the wind....

                                    J Offline
                                    J Offline
                                    jenya7
                                    wrote on last edited by jenya7
                                    #68

                                    @JonB
                                    viewfinder = new QCameraViewfinder(); is an empty object, not tied to any widget. in the original example viewfinder is tied to a StackedWidget panel.

                                    jsulmJ JonBJ 2 Replies Last reply
                                    0
                                    • jsulmJ jsulm

                                      @jenya7 said in A camera problem.:

                                      It's not physically allocated

                                      It is, see the first line in the constructor

                                      J Offline
                                      J Offline
                                      jenya7
                                      wrote on last edited by
                                      #69

                                      @jsulm said in A camera problem.:

                                      @jenya7 said in A camera problem.:

                                      It's not physically allocated

                                      It is, see the first line in the constructor

                                      It doesn't work

                                      jsulmJ 1 Reply Last reply
                                      0
                                      • J jenya7

                                        @JonB
                                        viewfinder = new QCameraViewfinder(); is an empty object, not tied to any widget. in the original example viewfinder is tied to a StackedWidget panel.

                                        jsulmJ Offline
                                        jsulmJ Offline
                                        jsulm
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #70

                                        @jenya7 said in A camera problem.:

                                        viewfinder = new QCameraViewfinder(); is an empty object, not tied to any widget.

                                        It's not "empty". And a widget does not have to be "tied" to another widget. If it is not and you call show() on it it will be shown in its own window, but it should not crash...

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

                                        J 1 Reply Last reply
                                        0
                                        • J jenya7

                                          @jsulm said in A camera problem.:

                                          @jenya7 said in A camera problem.:

                                          It's not physically allocated

                                          It is, see the first line in the constructor

                                          It doesn't work

                                          jsulmJ Offline
                                          jsulmJ Offline
                                          jsulm
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #71

                                          @jenya7 said in A camera problem.:

                                          It doesn't work

                                          What doesn't work? I'm sure that line works. Do you call show() after that line or before?

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

                                          1 Reply Last reply
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