[Interest] QVideoFrame and YUV question

[Rayner Pupo]

Hi, I'm trying to create a QImage from a QVideoFrame but my video has YUV420P 
format so converting it's not easy for me at all. By using a snippet from 
histogram class from the player example provided by Qt I was able to read each 
pixel on the frame but my question is: who can I decompose Y, Cb and Cr values 
from a single uchar?
This is how to I'm iterating over the video frame bits.
if (videoFrame.pixelFormat() == QVideoFrame::Format_YUV420P) {
        QImage nImage(videoFrame.width(), videoFrame.height(), 
QImage::Format_RGB32);
        uchar *b = videoFrame.bits();
        for (int y = 0; y < videoFrame.height(); y++) {
            uchar *lastPixel = b + videoFrame.width();
            int wIndex = 0;
            for (uchar *curPixel = b; curPixel < lastPixel; curPixel++) {
                double y_ = *curPixel;????????
                double u_ = ???????????;
                double v_ = ???????????;

                r = y_ + 1.402 * v_;
                g = y_ - 0.344 * u_ - 0.714 * v_;
                b = y_ + u_ * 1.772;

                nImage.setPixel(wIndex, y, qRgb(int(r), int(g), int(b)));

                ++wIndex;
            }
            b += videoFrame.bytesPerLine();
        }
        return nImage;
}
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