Problem on QCamera auto exposure

[WangZiqi]

Hi!
I use qt for starting camera and recording on Windows. And I met some questions.
I need to set my camera auto exposure (if it's support) so I write code like this.

//Before these codes I new a object of QCamera(m_camera) and set what I need
        QCameraExposure *exposure = m_camera->exposure();
	auto curExposureMode = exposure->exposureMode();
	auto isSupportExposureAuto = exposure->isExposureModeSupported(QCameraExposure::ExposureAuto);
	exposure->setExposureMode(QCameraExposure::ExposureAuto);
        m_camera->start();

And the result is: curExposureMode is "QCameraExposure::ExposureAuto" and isSupportExposureAuto is false. But I see with AMCap, my camera is support auto exposure and I have set the exposure to manual mode before. And after I set the exposure auto, there is nothing changed on my camera(it is still manual exposure mode).

So is there anyone can tell me what's wrong with my code?
Thanks!

[SGaist]

Hi and welcome to devnet,

What version of Qt are you using ?
What is AMCap ?
What does it use to communicate with that camera ?

You don't have anything wrong in your code. The backend used to communicate with the camera however might not be able to set the exposure.

[WangZiqi]

Thanks for your help.
The version of QT is 5.7.0.
"AMCap" is a software that can tell me whether the camera is support auto exposure and other settings. You can download here(https://amcap.en.softonic.com/).
I use AMCap and set my camera auto exposure, it runs good.So I think my camera is support auto exposure.But with the follow code I get the different answer.

auto isSupportExposureAuto = exposure->isExposureModeSupported(QCameraExposure::ExposureAuto);
//the result is false

[SGaist]

You should use a more recent version of Qt.
The current release is 5.11, LTS is 5.9 and 5.12 is around the corner.

[WangZiqi]

OK, I will try again with Qt5.11.0. Thank you very much!