QT QCamera vs QML Quick Camera Performance

Hi. All.
I’m beginner to study embedded linux with QT on Apalis i.mx6.
I have already installed QT creator 4.10 (enterprise) that downloaded from QT web site.
Also installed Boot to QT on apalis i.mx6 using toradex easy installer.
Recently I’m testing display from toradex analog CAMERA module.
In case of Testing “QML Camera Example” (QT Example), I statisfied the performance result.
https://doc.qt.io/qt-5/qtmultimedia-multimedia-declarative-camera-example.html

but In case of Testing “QCamera Example”, the result was not good at me.
there was some delay on display camera.
https://doc.qt.io/qt-5/qtmultimedia-multimediawidgets-camera-example.html

What’s different between QML Camera and QCamera performance?

I want to develop my project using based QCamera example.

are there some example that high performance with QCamera?

Dear @wolfkim71

If you’re using boot2qt maybe the Qt Company can give you a better idea of what is going wrong in the second example.

However, as I underatand QML Camera basically instanciates QCamera directly. So probably not QCamera is the problem but QWidgets/QMainWindow. When using QtDeclarative the GPU is used for handling the Window content (e.g. the image) while for QMainWindow it’s done in Software. Maybe there is some Color convertion done in Software in the second example, when it is done on GPU in the first one.

Why do you want to avoid QtDeclarative/QtQuick? I think for new applications it’s better to use QtQuick than old style Widgets.

Regards,
Stefan

Thank you for your answer.

I’ve been using C++ for a long time. Therefore, C++ is more familiar than QML.
it might be better to study QtQuick anew than to find a solution in the second example.

Thanks your advice.

Best regards…

Hi @wolfkim71

You are welcome.

Best regards,
Jaski