QML Camera does not work on android!

[Mesrine]

Hello everyone,

I am testing a qr decoder using android
the custom qml type-file is

import QtQuick 2.0
import QtMultimedia
import QtQrDec
import MyDesigns

Item
{
    id:root
    signal gotdata(string data);
    function stop() {
        timer.stop();
        camera.stop();
        startcamera.visible=true;
    }

    VideoOutput {
        id: videoOutput
        anchors.fill: root
    }
    MediaDevices {
        id: devices
    }
    Camera {
        id: camera
        active: false
        cameraDevice: devices.defaultVideoInput
        onErrorOccurred: (error,errorString)=> {
                             console.log( devices.videoInputs);
                             console.log(errorString)
                             console.log(error)
                         }

    }
    Connections {
        target: QRImageDecoder
        function onText_changed(boo) {
            root.gotdata(QRImageDecoder.text)
        }
    }
    Connections {
        target: QRImageDecoder
        function onPermissionRequested(boo) {
            if(boo)
            {
                console.log( devices.videoInputs);
                console.log(camera.cameraFormat)

                devices.videoInputs.forEach((Cdev)
                                            => {
                                                if(Cdev.position===Cdev.BackFace)
                                                {
                                                    camera.cameraDevice=Cdev;
                                                }
                                            });


                camera.start();
                timer.start();
                startcamera.visible=false;
            }
        }
    }

    CaptureSession {
        id: capturesession
        camera: camera
        videoOutput: videoOutput
        imageCapture: ImageCapture {
            id: imageCapture
            onErrorOccurred:(requestId, error, message)=> {
                                console.log("capture error:",message)

            }

            onImageCaptured: {
                console.log("onImageCaptured");
                QRImageDecoder.source = imageCapture.preview
            }

        }
    }
    Timer {
        id: timer
        interval: 500; running: false; repeat: true
        onTriggered:
        {
            console.log("camera:",camera.cameraFormat.pixelFormat)
            if( imageCapture.readyForCapture )
            {
                imageCapture.capture();
            }
        }
    }
    MyButton
    {
        id:startcamera
        anchors.centerIn: root
        text:qsTr("ScanQr")
        onClicked:
        {
            QRImageDecoder.requestPermision();
        }
        width:100
        height:width*0.5
    }
}

The thing is that when pressing the 'ScanQr' button, the app ask for permission to use the camera. If the permission is granted The video is shown on the app but the video is lagging.
And the imageCapture.readyForCapture is always false.

On the debugger, I get:

W Gralloc4: allocator 3.x is not supported
W Gralloc3: allocator 3.x is not supported
W ample.nftminte: [SurfaceTexture-4-9500-0] bindTextureImage: clearing GL error: 0x500
W ample.nftminte: [SurfaceTexture-4-9500-0] bindTextureImage: clearing GL error: 0x500

Any help will be much appreciated.
Thank you for your time.

[Mesrine]

@Mesrine

I have tried the declarative camera example on Android and it works ok. It also returns the same warnings

W Gralloc4: allocator 3.x is not supported
W Gralloc3: allocator 3.x is not supported
W ample.nftminte: [SurfaceTexture-4-9500-0] bindTextureImage: clearing GL error: 0x500
W ample.nftminte: [SurfaceTexture-4-9500-0] bindTextureImage: clearing GL error: 0x500

The video is lagging on my app because calling imageCapture.capture() freezes the VideoOutput. This freeze does not happen on the Desktop.
Do you think it freezes because of memory issues or is it a feature?

[ekkescorner]

@Mesrine said in QML Camera does not work on android!:

lagging

don't know if this is the reason of your problems, but your QML Camera classes structure isn't valid from my POV: Camera should be inside CaptureSession
see here my blog about Port QML Camera 5.15 to 6.6

[Mesrine]

@ekkescorner
Thanks, I am no longer using imageCapture.capture(). I do not understand the difference between declaring the camera outside the CaptureSession and inside the CaptureSession. There is no warning or a mandatory statement about this in the documentation, or there is?

[ekkescorner]

@Mesrine you're right. have overlooked that inside CaptureSession you set camera: camera