QMediaPlayer QML绑定问题

Question

我希望实现一个将在QML上显示的QMediaPlayer视频流。我试图扩展QMediaPlayer类并在MyMediaPlayer类下面创建。我在main.cpp文件中实例化该类以在GUI上显示它。即使没有错误，视频在QML窗口上也不可见。我的错在哪里？

mymediaplayer.cpp

#include "MyMediaPlayer.h"

MyMediaPlayer::MyMediaPlayer(QObject* parent, Flags flags): QMediaPlayer(parent, flags)
{
}

void MyMediaPlayer::setVideoSurface(QAbstractVideoSurface* surface)
{
    qDebug() << "Changing surface";
    m_surface = surface;
    setVideoOutput(m_surface);
}

QAbstractVideoSurface* MyMediaPlayer::getVideoSurface()
{
    qDebug() << "Surface Got";
    return m_surface;
}

mymediaplayer.h

#ifndef MYMEDIAPLAYER_H
#define MYMEDIAPLAYER_H
#include <QMediaPlayer>

class MyMediaPlayer: public QMediaPlayer
{
    Q_OBJECT
    Q_PROPERTY(QAbstractVideoSurface* videoSurface READ getVideoSurface WRITE setVideoSurface )

public:
    MyMediaPlayer(QObject * parent = 0, Flags flags = 0);

public slots:
    //virtual void play(const QString& strFile);
    void setVideoSurface(QAbstractVideoSurface* surface);
    QAbstractVideoSurface* getVideoSurface();

private:
    QAbstractVideoSurface* m_surface;
};

#endif // MYMEDIAPLAYER_H

的main.cpp

 MyMediaPlayer* player = new MyMediaPlayer();


engine.rootContext()->setContextProperty("mediaplayer", player);

QQuickView view;
view.engine()->rootContext()->setContextProperty("mediaplayer", player);

player->setMedia(QUrl(QStringLiteral("qrc:/1.mp4")));
qDebug() << "media set";
player->play();
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

main.qml

VideoOutput {
        z: 1000
        id: videooutput
        width: 320
        height: 240
        source: mediaplayer
    }