vo->receive(VideoFrame(qt_image));. Main event loop is required to show the image. So if you want to show when startup, you can QTimer::singleShot(0, [=](){vo->receive(VideoFrame(qt_image));});

In QML, you can use multiple Subtitle objects and corresponding SubtitleItem, and set property Subtitle.fuzzyMatch to false, Subtitle.file to a subtitle path. C++ app is almost the same, using multiple SubtitleFilter objects and set properties. Actually each QML Subtitle object use an C++ VideoFilter internally.

see https://github.com/wang-bin/QtAV/issues/637

m_player->setStartPosition(1);

connect(m_player, SIGNAL(seekFinished(qint64)), this, SLOT(pauseOnSeek())); ... void PlayerWindow::pauseOnSeek() { m_player->pause(true); disconnect(m_player, SIGNAL(seekFinished(qint64)), this, SLOT(pauseOnSeek())); }