Error displaying video from the camera

DQUY05

Hi everyone !

I am having an error displaying video from the camera (I use qt5.15, arm64-v8a.so, android-9 phone )

W libuntitled_arm64-v8a.so: The video surface is not compatible with any format supported by the camera

My code

   camera = new QCamera();
   viewfinder = new QCameraViewfinder();
   camera->setViewfinder(viewfinder);
   viewfinder->show();
   camera->start();

thanks in advance !

nagesh

@DQUY05 setViewfinder call sets a video surface as the viewfinder of a camera.
camera & viewfinder are default constructed object. Which camera device do you want to open?

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

const QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
for (const QCameraInfo &cameraInfo : cameras) {
if (cameraInfo.deviceName() == "mycamera")
camera = new QCamera(cameraInfo);
}

DQUY05

@nagesh said in Error displaying video from the camera:

const QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
for (const QCameraInfo &cameraInfo : cameras) {
if (cameraInfo.deviceName() == "mycamera")
camera = new QCamera(cameraInfo);
}

Thank you for your help !
I tried as below, but still get the same error message : W libuntitled_arm64-v8a.so: The video surface is not compatible with any format supported by the camera

     const QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
     for (const QCameraInfo &cameraInfo : cameras) {
         if (cameraInfo.deviceName() == "back")
         {
             qDebug() <<"video start";
             camera = new QCamera(cameraInfo);
             viewfinder = new QCameraViewfinder();
             viewfinder->showMaximized();
             camera->setCaptureMode(QCamera::CaptureViewfinder);
             camera->setViewfinder(viewfinder);
             viewfinder->show();
             camera->start();
             qDebug() <<"video finish";
         }
     }

I think the video format is not suitable for my phone, but I don't know how to convert it
Regards !

nagesh

@DQUY05 said in Error displaying video from the camera:

The video surface is not compatible with any format supported by the camera

There was some discussion regarding this topic.
https://forum.qt.io/topic/93173/camera-access-in-android-device

There is Camera example in Qt.

you also need to check whether mode is supported before calling setCaptureMode using isCaptureModeSupported(QCamera::CaptureViewfinder)

DQUY05

@nagesh said in Error displaying video from the camera:

@DQUY05 said in Error displaying video from the camera:

The video surface is not compatible with any format supported by the camera

There was some discussion regarding this topic.
https://forum.qt.io/topic/93173/camera-access-in-android-device

There is Camera example in Qt.

you also need to check whether mode is supported before calling setCaptureMode using isCaptureModeSupported(QCamera::CaptureViewfinder)

it has support (ui->inform->setText("with support");)

     const QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
     for (const QCameraInfo &cameraInfo : cameras) {
         if (cameraInfo.deviceName() == "back")
         {
             camera = new QCamera(cameraInfo);
             if(camera->isCaptureModeSupported(QCamera::CaptureViewfinder))
             {
             ui->inform->setText("with support");
             }
             viewfinder = new QCameraViewfinder();
             viewfinder->setMinimumSize( 50, 50 );
             camera->setCaptureMode(QCamera::CaptureViewfinder);
             camera->setViewfinder(viewfinder);
             viewfinder->show();
             camera->start();
         }
     }

Can you show me how to use the QVideoFrame :: Format_NV21 converter?
https://forum.qt.io/topic/93173/camera-access-in-android-device

Many thanks!

nagesh

@DQUY05 I never used Qmultimedia module..

check in the below link qt docs..
https://doc.qt.io/qt-5/android-platform-notes.html
it says
The Qt Multimedia Widgets module is not supported on Android, which means video display is only available using the Video QML Type.

DQUY05

@nagesh said in Error displaying video from the camera:

@DQUY05 I never used Qmultimedia module..

check in the below link qt docs..
https://doc.qt.io/qt-5/android-platform-notes.html
it says
The Qt Multimedia Widgets module is not supported on Android, which means video display is only available using the Video QML Type.

Thank you !

I have never written in QML before, but I must try it

DQUY05

@nagesh said in Error displaying video from the camera:

@DQUY05 I never used Qmultimedia module..

check in the below link qt docs..
https://doc.qt.io/qt-5/android-platform-notes.html
it says
The Qt Multimedia Widgets module is not supported on Android, which means video display is only available using the Video QML Type.

Hi Mr.
I tried with QML to get video from camera, rendering on QML is fine, but c ++ has connection but no output image in SLOT, i spend a lot of time but still no result

.qml

    Camera
    {
        id: camera
        objectName: "set_camera"

        imageProcessing.whiteBalanceMode: CameraImageProcessing.WhiteBalanceFlash

        exposure
        {
            exposureCompensation: -1.0
            exposureMode: Camera.ExposurePortrait
        }

        focus
        {
            focusMode: Camera.FocusContinuous
            focusPointMode: Camera.FocusPointCenter
        }

        flash.mode: Camera.FlashRedEyeReduction  // giảm hiệu ứng mắt đỏ flash

        imageCapture
        {
            onImageCaptured:
            {
                photoPreview.source = preview  // Show the preview in an Image
            }
        }

    }

    VideoOutput
    {
        orientation: 270  // xoay khung camera
        source: camera
        anchors.fill: parent
        focus : false // to receive focus and capture key events when visible
    }

.cpp

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/motlan.qml")));

    QObject *qmlCamera = engine.rootObjects().at(0)->findChild<QObject*>("set_camera");
    ui->inform->setText(qmlCamera->objectName());  // I test show is fine !
    QCamera *camera1 = qvariant_cast<QCamera*>(qmlCamera->property("mediaObject"));   

    probe_.setSource(camera1);
    connect(&probe_,SIGNAL(videoFrameProbed(const QVideoFrame &)),
                    this, SLOT(present(const QVideoFrame &)));

Thanks !

SGaist

Hi,

What do you mean by "no output image in slot" ?

DQUY05

@SGaist said in Error displaying video from the camera:

Hi,

What do you mean by "no output image in slot" ?

Yes, I mean I don't get a signal or signal that is not in QVideoFrame format, or when I switch to Widget environment, qml is disabled when win.show():

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow win;

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/motlan.qml")));

    QTest::qWait(5000);

    win.show();
    return a.exec();
}

Many thanks!

SGaist

It looks like you are trying to do some strange mix.

What is your exact goal with your application ?

DQUY05

@SGaist said in Error displaying video from the camera:

It looks like you are trying to do some strange mix.

What is your exact goal with your application ?

My aim is to get video from camera using Qml, then pass real-time VideoFrame into Ui :: MainWindow widget, (because I tried a lot of different ways to get Video Camera on Ui :: MainWindow widget but failed)
To me this is very important, I am stuck !

Thanks!

SGaist

If you use a QQuickWidget properly you'll have your QtQuick interface show in your QMainWindow.

WXJ0620

@DQUY05 I had the same problem. Have you solved it now?Thanks