Unable to run QT Camera Example on Qt 5.9.1

[hrithik singh]

I am trying to run the camera example provided by Qt and it keeps throwing an error in debug mode " write access violation" (ref. screen shot).

[jsulm]

@hrithik-singh You should build it in debug mode, then you should see more than assembly when it crashes...

[J.Hilk]

@jsulm I think this is the debugger already, see the play icon on the left side.

@hrithik-singh click on the level 6 entry I believe thats the camera.cpp class that's called there, should give more info, where the error originates from.

[jsulm]

@J.Hilk Yes, but the build is a release build

[hrithik singh]

@jsulm yes i changed it to release build still shows me the same

[jsulm]

@hrithik-singh Can you show the whole method body above line 182?

[hrithik singh]

@J.Hilk when i click on level 6 it takes me to this loadCamerq session part of ca mera.cpp

[J.Hilk]

@hrithik-singh
thats a different log file now. Now its level 7 qcamera.cpp, but thats still to deep, thats part of the Qt-lib. You need to go further back, untill the file name fits one of those in the project.

[hrithik singh]

@jsulm this is the method i have just removed all the qinfo lines that I added. then rerun the build; got the same error.
void Camera::setCamera(const QCameraInfo &cameraInfo)
{
delete imageCapture;
delete mediaRecorder;
delete camera;
camera = new QCamera(cameraInfo);
connect(camera, SIGNAL(stateChanged(QCamera::State)), this, SLOT(updateCameraState(QCamera::State)));
connect(camera, SIGNAL(error(QCamera::Error)), this, SLOT(displayCameraError()));
mediaRecorder = new QMediaRecorder(camera);
connect(mediaRecorder, SIGNAL(stateChanged(QMediaRecorder::State)), this, SLOT(updateRecorderState(QMediaRecorder::State)));
imageCapture = new QCameraImageCapture(camera);
connect(mediaRecorder, SIGNAL(durationChanged(qint64)), this, SLOT(updateRecordTime()));
connect(mediaRecorder, SIGNAL(error(QMediaRecorder::Error)), this, SLOT(displayRecorderError()));
mediaRecorder->setMetaData(QMediaMetaData::Title, QVariant(QLatin1String("Test Title")));
connect(ui->exposureCompensation, SIGNAL(valueChanged(int)), SLOT(setExposureCompensation(int)));
camera->setViewfinder(ui->viewfinder);
updateCameraState(camera->state());
updateLockStatus(camera->lockStatus(), QCamera::UserRequest);
updateRecorderState(mediaRecorder->state());
connect(imageCapture, SIGNAL(readyForCaptureChanged(bool)), this, SLOT(readyForCapture(bool)));
connect(imageCapture, SIGNAL(imageCaptured(int,QImage)), this, SLOT(processCapturedImage(int,QImage)));
connect(imageCapture, SIGNAL(imageSaved(int,QString)), this, SLOT(imageSaved(int,QString)));
connect(imageCapture, SIGNAL(error(int,QCameraImageCapture::Error,QString)), this,
SLOT(displayCaptureError(int,QCameraImageCapture::Error,QString)));
connect(camera, SIGNAL(lockStatusChanged(QCamera::LockStatus,QCamera::LockChangeReason)),
this, SLOT(updateLockStatus(QCamera::LockStatus,QCamera::LockChangeReason)));
ui->captureWidget->setTabEnabled(0, (camera->isCaptureModeSupported(QCamera::CaptureStillImage)));
ui->captureWidget->setTabEnabled(1, (camera->isCaptureModeSupported(QCamera::CaptureVideo)));
updateCaptureMode();
camera->start();
}

[hrithik singh]

@J-Hilk when i traverse down it goes to camera.cpp and camera-start for I posted the complete method above

[mranger90]

@hrithik-singh said in Unable to run QT Camera Example on Qt 5.9.1:

imageCapture

Looking at the code above the one thing I'd try is make sure that camerInfo.isNull() is not true. Or you can try to construct the camera with QCameraInfo::defaultCamera().
Hard to say because we dont know where cameraInfo comes from.
If that camera pointer is not valid, then all bets are off and its certain that a crash will happen further in the code.

[hrithik singh]

@mranger90
we are using this hybrid machine
Below is the spec

http://www.wortmann.asia/data/album/file/1530168638752052316.pdf

camera settings:

Hi

Video Capture Devices
Number of Devices: 2

       FriendlyName: User Facing Right
           Category: Camera
       SymbolicLink: \\?\display#int3470#4&5dbfe47&0&uid13424#{e5323777-f976-4f5b-9b55-b94699c46e44}\{089f8e59-ffe6-4494-97e5-92273c08f2f1}
           Location: Front
           Rotation: 0
       Manufacturer: Intel Corporation
         HardwareID: VIDEO\VEN_8086&DEV_591E&SUBSYS_224317AA&REV_02&INT3470,VIDEO\VEN_8086&DEV_591E&SUBSYS_224317AA&INT3470,VIDEO\VEN_8086&DEV_591E&INT3470,VIDEO\INT3470
         DriverDesc: Intel(R) AVStream Camera 2500
     DriverProvider: Intel
      DriverVersion: 30.14393.9656.3064
  DriverDateEnglish: 9/23/2016 00:00:00
DriverDateLocalized: 23/09/2016 00:00:00
            Service: iacamera64
              Class: MEDIA
      DevNodeStatus: 180200A[DN_DRIVER_LOADED|DN_STARTED|DN_DISABLEABLE|DN_NT_ENUMERATOR|DN_NT_DRIVER]
        ContainerId: {00000000-0000-0000-FFFF-FFFFFFFFFFFF}
        ProblemCode: No Problem

BusReportedDeviceDesc: ISP Camera Device
Parent: PCI\VEN_8086&DEV_591E&SUBSYS_224317AA&REV_02\3&11583659&1&10
DriverProblemDesc: n/a
UpperFilters: n/a
LowerFilters: n/a
Stack: \Driver\ksthunk,\Driver\iacamera64,\Driver\igfx
ContainerCategory: n/a
SensorGroupID: n/a
MFT0: {5CDB3151-134C-4622-8E44-FAA9158D2F4C}
DMFT: n/a
DependentStillCapture: n/a
EnablePlatformDMFT: n/a
DMFTChain: n/a
EnableDshowRedirection: n/a
FrameServerEnabled: False

       FriendlyName: World Facing Right
           Category: Camera
       SymbolicLink: \\?\display#int3470#4&5dbfe47&0&uid13424#{e5323777-f976-4f5b-9b55-b94699c46e44}\{ce46c6bb-90df-4932-8ec1-add1804961a1}
           Location: Back
           Rotation: 0
       Manufacturer: Intel Corporation
         HardwareID: VIDEO\VEN_8086&DEV_591E&SUBSYS_224317AA&REV_02&INT3470,VIDEO\VEN_8086&DEV_591E&SUBSYS_224317AA&INT3470,VIDEO\VEN_8086&DEV_591E&INT3470,VIDEO\INT3470
         DriverDesc: Intel(R) AVStream Camera 2500
     DriverProvider: Intel
      DriverVersion: 30.14393.9656.3064
  DriverDateEnglish: 9/23/2016 00:00:00
DriverDateLocalized: 23/09/2016 00:00:00
            Service: iacamera64
              Class: MEDIA
      DevNodeStatus: 180200A[DN_DRIVER_LOADED|DN_STARTED|DN_DISABLEABLE|DN_NT_ENUMERATOR|DN_NT_DRIVER]
        ContainerId: {00000000-0000-0000-FFFF-FFFFFFFFFFFF}
        ProblemCode: No Problem

BusReportedDeviceDesc: ISP Camera Device
Parent: PCI\VEN_8086&DEV_591E&SUBSYS_224317AA&REV_02\3&11583659&1&10
DriverProblemDesc: n/a
UpperFilters: n/a
LowerFilters: n/a
Stack: \Driver\ksthunk,\Driver\iacamera64,\Driver\igfx
ContainerCategory: n/a
SensorGroupID: n/a
MFT0: {5CDB3151-134C-4622-8E44-FAA9158D2F4C}
DMFT: n/a
DependentStillCapture: n/a
EnablePlatformDMFT: n/a
DMFTChain: n/a
EnableDshowRedirection: n/a
FrameServerEnabled: False

[J.Hilk]

@hrithik-singh
mmh, simple question first. Does the normal Qt-Camera example work fine for you ?

https://doc.qt.io/qt-5.11/qtmultimedia-multimediawidgets-camera-example.html

[mranger90]

@J.Hilk I thought the OP was working with the multimediawidget camera example.
@hrithik singh What I would do next is put a breakpoint (or debug statements) in the
Camera::Camera : ui(new Ui::Camera) method.
Take a look at the list of available cameras and see what is being found.
You can also look at the description of the QCameraInfo::defaultCamera().

[J.Hilk]

@mranger90
Well the Code the op posted is defenitely modified

Thats why I suggested the default exmaple, to see if at least that works

[hrithik singh]

@mranger90
start() method throws access violation, I can get the camera information

[hrithik singh]

@J.Hilk nope doesn't work.