A camera problem.
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@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 -
@jenya7 Please run through debugger and post the stack trace.
Also, you should post your current code with enabled viewfinder.@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 -
@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 -
@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.
@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 -
@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 -
@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?
@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()); } -
@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()); } -
@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?
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@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(); -
@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();@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? -
@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?@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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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. -
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. -
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.@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.
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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.
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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.
@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.
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@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.
@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 thoughtconnect()would barf on that.... Try using void QCameraImageCapture::readyForCaptureChanged(bool ready) signal? -
@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 thoughtconnect()would barf on that.... Try using void QCameraImageCapture::readyForCaptureChanged(bool ready) signal?@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 thoughtconnect()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
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@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 thoughtconnect()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
@jenya7 said in A camera problem.:
never get into ReadyForCaptureChanged
Sure? How did you verify that?
