QCamera seems broken

Question

In order to use my phone camera (on a Nexus 5) I use this code :

camera = new QCamera;
camera->setViewfinder(ui->viewFinder);
ui->viewFinder->show();

ui->stackedWidget->setGeometry(0,0, 1000, 1700);
ui->viewFinder->setGeometry(0, 0, 1000, 1700);

camera->start(); // to start the viewfinder
qDebug() << camera->error() << camera->errorString();
qDebug() << camera->state() << camera->status();

coming from the Qt doc but it doesn't do anything. I've added the correct includes in the header file and the QT += multimedia multimediawidgets in the .pro file.

The output is :

QCamera::NoError ""
QCamera::UnloadedState QCamera::UnloadedStatus

Which is kind of weird because if the start() function fails it should throw an error :

void QCamera::start() [slot] Starts the camera.

State is changed to QCamera::ActiveState if camera is started successfully, otherwise error() signal is emitted.

While the camera state is changed to QCamera::ActiveState, starting the camera service can be asynchronous with the actual status reported with QCamera::status property.

EDIT

QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
foreach (const QCameraInfo &cameraInfo, cameras) {
qDebug() << cameraInfo.deviceName();
}

Outputs :

"back"

"front"

So QT detects the devices.

EDIT 2

Here's some log which seems to contain a few errors but as it's my first android app, I not totally aware of what's going on :

D/dalvikvm(21060): GC_CONCURRENT freed 172K, 2% free 17025K/17228K, paused 5ms+1ms, total 22ms
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libgnustl_shared.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libgnustl_shared.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/data/org.qtproject.example.HUD/lib/libgnustl_shared.so 0x42cb2588, skipping init
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5Core.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5Core.so 0x42cb2588
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5Gui.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5Gui.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/data/org.qtproject.example.HUD/lib/libQt5Gui.so 0x42cb2588, skipping init
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5Network.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5Network.so 0x42cb2588
I/Qt      (21060): Network start
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5Multimedia.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5Multimedia.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/data/org.qtproject.example.HUD/lib/libQt5Multimedia.so 0x42cb2588, skipping init
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5Widgets.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5Widgets.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/data/org.qtproject.example.HUD/lib/libQt5Widgets.so 0x42cb2588, skipping init
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5OpenGL.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5OpenGL.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/data/org.qtproject.example.HUD/lib/libQt5OpenGL.so 0x42cb2588, skipping init
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5MultimediaWidgets.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5MultimediaWidgets.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/data/org.qtproject.example.HUD/lib/libQt5MultimediaWidgets.so 0x42cb2588, skipping init
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/lib/libQt5Positioning.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/lib/libQt5Positioning.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/data/org.qtproject.example.HUD/lib/libQt5Positioning.so 0x42cb2588, skipping init
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/qt-reserved-files/plugins/platforms/android/libqtforandroid.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/qt-reserved-files/plugins/platforms/android/libqtforandroid.so 0x42cb2588
I/Qt      (21060): qt start
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/qt-reserved-files/plugins/mediaservice/libqtmedia_android.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/qt-reserved-files/plugins/mediaservice/libqtmedia_android.so 0x42cb2588
D/dalvikvm(21060): Trying to load lib /data/data/org.qtproject.example.HUD/qt-reserved-files/plugins/position/libqtposition_android.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/data/org.qtproject.example.HUD/qt-reserved-files/plugins/position/libqtposition_android.so 0x42cb2588
I/QtPositioning(21060): Positioning start
D/dalvikvm(21060): Trying to load lib /data/app-lib/org.qtproject.example.HUD-1/libHUD.so 0x42cb2588
D/dalvikvm(21060): Added shared lib /data/app-lib/org.qtproject.example.HUD-1/libHUD.so 0x42cb2588
D/dalvikvm(21060): No JNI_OnLoad found in /data/app-lib/org.qtproject.example.HUD-1/libHUD.so 0x42cb2588, skipping init
I/Adreno-EGL(21060): <qeglDrvAPI_eglInitialize:320>: EGL 1.4 QUALCOMM Build: I0404c4692afb8623f95c43aeb6d5e13ed4b30ddbDate: 11/06/13
D/OpenGLRenderer(21060): Enabling debug mode 0

Answer 1

I think the answer to your question is contained here;

https://bugreports.qt-project.org/browse/QTBUG-38233?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Basically - it isn't working.

I can confirm the camera never moves into mode 8 under 5.3 branch of QT. 5.2.1 allows images to be captured, but the viewfinder does not work.

I'm not sure what is going on, or why they would've stopped supporting this code.