Access IP camera from Qt

SGaist

Are you doing any blocking function call ? e.g. for your serial port ?

mkrr

@SGaist No, I'm using a Qthread to execute the serial port

SGaist

Can you describe the various parts of your application so we can ensure that they are not influencing each other.

By the way, there's no need to set cache each time. Just set the property where you declarer image1. That's one less thing consuming time uselessly.

mkrr

@SGaist It's my main function:

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QDeclarativeView *engine = new QmlApplicationViewer();
    
    Gps *gps = new Gps(); // Class to read Gps (serial port 0). Interval: 10000ms
    
    SerialPort *serial = new SerialPort(); // Read Serial Port (serial port 1). Interval: 300ms
    
   if(serial->getMonitor()) {
        qDebug() << "Starting Monitor";
        Monitor *monitor = new Monitor(engine, serial);
        serial->setMonitor(monitor);
    }
    return app.exec();
}

The class SerialPort start the write on serial port with a forever loop. Its working well, without delays.

When the serial read the response, the response is sent to monitor Class and this class is responsable to format the digits and write on screen (QML file). Therefore, each 300 ms my QML file is updated too (with the response of serial port).

SGaist

Then where's the camera in that setup ?

mkrr

@SGaist The camera is loaded in a different QML, look:

import QtQuick 1.1

Rectangle {
    width: 300
    height: 400

    Image {
        id: camera1
        objectName: "camera1"
        x: 39
        y: 0
        width: 160
        height: 120
        source: "http://192.168.0.110/image/jpeg.cgi"
        cache: false

        Timer {
            interval: 300
            running: true
            repeat: true
            onTriggered: {
                camera1.source = "http://192.168.0.110/image/jpeg.cgi";
            }
        }
    }
...
}

The QML is loaded on Monitor class:

Monitor::Monitor(QDeclarativeView *engine, Monitor *m)
{
    engine->setSource(QUrl("qrc:/views/Monitor.qml"));

    window = qobject_cast< QObject * >( engine->rootObject() );

    engine->showFullScreen();
    monitor = m;

    engine->rootContext()->setContextProperty("mainmonitor",this);
}

kolegs

You can also try to load next image when previous one is loaded by checking the status.
I use this in my application when loading jpeg from cameras.
You just need to set 2 Image objects and show them when Image is ready

mkrr

@kolegs how I can do to check the status? Could you show an exemple? Are you using the QML Time to update the frames? Thank you

kolegs

You just need to create two Images with same position add property

visible: status == Image.ready

and on also add sth like this

onStatusChanged:{
   if(status == Image.ready){
      //here reload the other image
      image2.source = "";
      image2.source = cameraSource;
   }
}

Add the same thing in image2 but this timer reload image1

onStatusChanged:{
   if(status == Image.ready){
      //here reload the other image
      image1.source = "";
      image1.source = cameraSource;
   }
}

Also at creation just set source to cameraSource for one image and for the other leave it empty,.

Hope it helps.

mkrr

@kolegs Thank you so much. I created this code and the performance was very better. I'm reading two IP cameras now with it.

Of course that the delay is existing (each 2 seconds the image is updated). I think that I need to improve my code. I'm using 98% of my CPU, but I need to do many routines :(

Thank you so much again

claudia0078

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