QWidget::paintEngine: Should no longer be called

[nadimfnadaf]

I try to capture a image of QVideoWidget using a grab()

But it capture a all black image.
and shows QWidget::paintEngine: Should no longer be called

player = new QMediaPlayer(this);
         vw = new QVideoWidget(this);
         player->setVideoOutput(vw);
        player->setMedia(QUrl("gst-pipeline: videotestsrc ! xvimagesink name=\"qtvideosink\""));
         vw->setGeometry(240,80,1400,800);
         vw->show();
         player->play();
          qDebug() << "clicked"
          vw->grab().save("image.png");

Any suggestion?

Thanks in advance.

[jsulm]

@nadimfnadaf said in QWidget::paintEngine: Should no longer be called:

player->play();
qDebug() << "clicked"
vw->grab().save("image.png");

You're trying to grab the image right after calling play(). At that time there is probably nothing to grab yet.
Try to connect a slot to https://doc.qt.io/qt-5/qmediaplayer.html#stateChanged and grab the image as soon as the state changes to QMediaPlayer::PlayingState.