[Interest] video init duration

["Alexander Carôt"]

see below - I just figured that this problem also occurs with the camera example:

https://doc.qt.io/qt-5/qtmultimedia-multimediawidgets-camera-example.html

On OSX it takes 35 seconds to process the first snapshot image - after that all is fine.

To me it looks like a bug, which I will report asap. If you doubt this is the case please let know.

Thanks and best

Alex


--
http://www.carot.de
Email : Alexander at Carot.de
Tel.: +49 (0)177 5719797


> Gesendet: Dienstag, 02. Oktober 2018 um 09:11 Uhr
> Von: "Alexander Carôt" <alexander_carot at gmx.net>
> An: "qt qt" <interest at qt-project.org>, olszak.tomasz at gmail.com
> Betreff: Re: [Interest] video init duration
>
> Hello Tomasz and all,
> 
> sorry for the late response - needed to figure several things first.
> 
> >>Have tried to wait until camera is in active status?
> 
> Yes, this is the case. Not that I consciously did that but the cam de facto is in active state.
> 
> >>And why you set timer interval to 40 ms?
> 
> Assuming a frame rate of 25 fps the capture interval is 40 ms.
> 
> In the meantime I figured that this 
> 
> Please find a minimal example app here, which shows my problem decribed below. It works fine on Linux, Windows and also Windows in a virtual Box on OSX but on native OSX I have this delay of 35 seconds until the sytems works:
> 
> https://www.dropbox.com/s/u6ifh6enco012xk/myCamera.zip?dl=0
> 
> Thanks,
> best
> 
> Alex
> 
> --
> http://www.carot.de
> Email : Alexander at Carot.de
> Tel.: +49 (0)177 5719797
> 
> 
> > Hi all,
> >
> > I have a video related app, which works fine but it takes 35 seconds after
> > initialization for the cam to work in single-capture modus. The code looks
> > like this:
> >
> > Camera::Camera() : ui(new Ui::Camera){
> >     ui->setupUi(this);
> >
> >     QCameraViewfinderSettings cameraSettings;
> >     cameraSettings.setMinimumFrameRate(25);
> >
> >     camera = new QCamera( QCameraInfo::defaultCamera() );
> >     imageCapture = new QCameraImageCapture(camera);
> >
> >     this->connect(imageCapture, &QCameraImageCapture::imageCaptured, this,
> > &Camera::imageCaptured);
> >
> >     camera->setViewfinder(ui->viewfinder);
> >
> >     captureTimer = new QTimer(this);
> >     captureTimer->setInterval(40);
> >     connect(captureTimer, SIGNAL(timeout()), this, SLOT(takePicture()));
> >     captureTimer->start();
> >
> >     camera->start();
> > }
> >
> > void Camera::imageCaptured(){
> >     cout << "IMAGE PROCESSED" << endl; /// THIS IS TRIGGERED THE FIRST
> > TIME AFTER 35 SECONDS
> > }
> >
> > void Camera::takePicture(){
> >     imageCapture->capture();
> > }
> >
> > This happens on OSX with the default inbuilt cam. I have not tested it on
> > other OSes yet but is there way to speed this time up or is it even a bug I
> > am having here ?
> >
> > Thanks in advance,
> > best
> >
> > Alex
> >
> >
> >
> > --
> > http://www.carot.de
> > Email : Alexander at Carot.de
> > Tel.: +49 (0)177 5719797
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