Android Qt 5.15 Camera: QCameraImageCapture error: "Camera not ready"

Nihilish

I'm trying to get the camera on an Android tablet to feed frames to a model I have that will analyze every frame. I don't want/need to show a viewfinder, as this is just background processing. I have tried a bunch of different things and I always end up with a variation of

'QCameraImageCapture error: "Camera not ready"'

Camera {
                id: camera
                captureMode: Camera.CaptureStillImage
                cameraState: Camera.ActiveState
                position: Camera.FrontFace

                imageCapture {
                    onReadyChanged: {
                        camera.imageCapture.capture()
                    }
                    onImageCaptured: {
                        console.log(requestId, preview)
                    }
                }
            }

            Component.onCompleted: {
                camera.start()
            }

This code is in my main QML container, it runs as soon the app is instantiated. The goal is for me to add a call to my model in onImageCaptured with the frame. But I get the "Camera not ready" error periodically.

What am I missing? I would do everything from the model with the QCamera object, but I've read that QCamera doesn't work on Android, only the QML Camera does. The weird thing is if I attach a VideoOutput component to the camera, I can see the camera feed. But imageCapture still. gives me that "Camera not ready error" error

mvuori

@Nihilish I don't know what is missing, but QCamera does work in Android

jsulm

@Nihilish said in Android Qt 5.15 Camera: QCameraImageCapture error: "Camera not ready":

What am I missing?

Access rights for the camera? On mobile platforms like Android your app needs to request access rights for the camera (and many other things).

Nihilish

@jsulm I did request and give permission to use the camera in the AndroidManifest. I noticed yesterday that even though I get the "camera not ready" error, the camera is taking and saving a bunch of pictures in /storage/emulated/0/DCIM/IMG_xxxx.jpg. So something is working but it's not triggering onImageCaptured

Nihilish

@mvuori said in Android Qt 5.15 Camera: QCameraImageCapture error: "Camera not ready":

@Nihilish I don't know what is missing, but QCamera does work in Android

Here's an attempt I made using QCamera by creating a CameraManager class that implements QAbstractVideoSurface. I would expect present and start to be called but they aren't.

#include "CameraManager.h"

#include <QQuickWindow>
#include <QWindow>
#include <QCameraViewfinder>
#include <QCameraInfo>

CameraManager::CameraManager(QObject *parent)
    : QAbstractVideoSurface{parent},
    mCamera(nullptr)
{
    QList<QCameraInfo> cameras = QCameraInfo::availableCameras(QCamera::Position::FrontFace);
    if (!cameras.isEmpty())
    {
        qDebug() << "HACK - CREATE CAMERA!!!";

        mCamera = new QCamera(cameras.first(), this);
        mCamera->setViewfinder(this);
        mCamera->setCaptureMode(QCamera::CaptureVideo);
        mCamera->start();

        qDebug() << "HACK - CAMERA STATE: " << mCamera->state();
        qDebug() << "HACK - CAMERA SUPPORTED FORMATS: " << mCamera->supportedViewfinderPixelFormats();
    }
}


bool CameraManager::start(const QVideoSurfaceFormat &format)
{
    qDebug() << "HACK - START!!!";

    if (!supportedPixelFormats(QAbstractVideoBuffer::NoHandle).contains(format.pixelFormat())) {
        return false;
    }
    return QAbstractVideoSurface::start(format);
}


bool CameraManager::present(const QVideoFrame &frame)
{
    qDebug() << "HACK - PRESENT FRAME";

    if (!frame.isValid())
        return false;

    emit frameAvailable(frame);
    return true;
}