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Hi,

I have a class Camera inheriting from cv::VideoCapture, which its core method is to convert a cv::Mat that I get from a live stream to a QImage :

QImage Camera::getFrame() {
    if(isOpened()) {
        cv::Mat image;
        (*this) >> image;
        cv::cvtColor(image, image, CV_BGR2RGB);
        return QImage((uchar*) image.data, image.cols, image.rows, image.step, QImage::Format_RGB888);
    }
    else return QImage();
}

And an encapsulating class CameraDelayedView which calls this method and adds a delay :

void CameraDelayedView::timerEvent(QTimerEvent *evt) {
    if(cam != NULL) {
        buffer.enqueue(cam->getFrame());

        if(buffer.size() > delay*fps) {
            setPixmap(QPixmap::fromImage(buffer.dequeue()));
        }
    }
}

The first frame is delayed like I want, but from that moment on, the video is a normal live feed like I would get without the queue system. Apparently, the images are part of a buffer which is updated, so that when creating a QImage with image.data, the pointers point at a frame which will be updated afterward. I want to avoid that: keep a snapshot, store it.

Do I have to copy each image.data myself to make it independant, or is there a more efficient way ? Please do not hesitate to tell me if the above can be more efficient as well.

Thanks in advance.

Regards, Mister Mystère