QT开发：使用QMediaPlayer在安卓设备上播放视频只有声音没有画面

代码如下：

    player = new QMediaPlayer(this);
    videoWidget = new QVideoWidget(this);
    videoWidget->resize(1000, 720);
    videoWidget->setAspectRatioMode(Qt::KeepAspectRatio);
    videoWidget->show();
    player->setVideoOutput(videoWidget)

运行时一连串不停的出现如下信息：

I BufferQueueProducer: [SurfaceTexture-0-6111-7](this:0xd6a1b000,id:7,api:3,p:499,c:6111) queueBuffer: slot 1 is dropped, handle=0xdd7e6960
I BufferQueueProducer: [SurfaceTexture-0-6111-7](this:0xd6a1b000,id:7,api:3,p:499,c:6111) queueBuffer: slot 10 is dropped, handle=0xd67030e0
I BufferQueueProducer: [SurfaceTexture-0-6111-7](this:0xd6a1b000,id:7,api:3,p:499,c:6111) queueBuffer: slot 2 is dropped, handle=0xd6702be0
I BufferQueueProducer: [SurfaceTexture-0-6111-7](this:0xd6a1b000,id:7,api:3,p:499,c:6111) queueBuffer: slot 3 is dropped, handle=0xdd7e6d20

没有装解码器？http://www.codecguide.com/