Get Camera's Resolutions

Suji

Hi guys !

I have a camera conected and I want to get its available resolutions. I can already display stream, and play with camera parameters like contrast, gamma, saturation, exposition etc.

I constructed a QCamera object like this :

QCamera m_camera = new QCamera;

Then i tried to do like this :

    if(m_camera!=NULL)
        m_camera->start();

    QCameraImageCapture * imageCapture = new QCameraImageCapture(m_camera);
    QImageEncoderSettings imageSettings;
    imageSettings.setResolution(3584, 2752);
    imageCapture->setEncodingSettings(imageSettings);

    QList<QSize> resolutions = imageCapture->supportedResolutions();
    std::cout << "Ready to use ? " << imageCapture->isAvailable() << std::endl;
    qDebug() << "Resolutions List : " << resolutions;

The first line returns true, but the second returns an empty list.

I have an empty list, moreover, when I verify, the resolution stay fixed to 896*688...

Do someone have an idea for my problem please ?

Have a nice day, you, who read my post ! :)

EDIT : if I use qDebug() << imageSettings.resolution(), that returns Qlist<3584, 2752> which is what I entered, but not what is displayed.

michelson

I think this one may come in handy:
https://forum.qt.io/topic/41412/how-to-get-camera-supported-resolutions-using-qt5/3
As far as i understnad you have to call load() function to get acces to resolutions.

Suji

Hi @michelson ! Thanks for your answer!

I saw this topic, but i though that my start() is similar to load(). I'll try the load() so.

Suji

Finally, that changed nothing... i still can't change my resolution...

michelson

Im sorry but I think its not your fault that the resolutions are not showing up on screen. Ive seen some more discutions about it and I guess someone has already reported this as a bug

https://bugreports.qt.io/browse/QTBUG-32743

I guess your only option now is to either use camera API or try to apply resolution fixed by yourself (if possible).

Suji

Hi @michelson !

Yes, i finally found this bug report too, but i forgot to post it yesterday. The table which Yoann Lopes gave (in your link) explains what is possible or not to do : http://wiki.qt.io/Qt_5.5.0_Multimedia_Backends.

Thanks for your help again ! I'll use my camera API then.

Have a nice day !