Ubuntu系统 qt下使用QMediaPlayer+QMediaPlayerlist视频播放 cpu占用过高问题，以及再同一个父类里导致QTimer 失效问题

项目开发过程中 ， 设备需要不断循环的播放同一个视频广告，网上很多例子是调用QMediaPlaylist+QMediaPlayer来实现循环的，但是这样会导致系统cpu占用率很高，容易导致视频卡主，黑屏的原因，

解决方法：

不使用QMediaPlayerlist 来进行循环 ；

QMediaPlayer new的时候不绑定父类；

V_widget=new QVideoWidget();

MC_player=new QMediaPlayer();

 MC_player->setMedia(QMediaContent(QUrl::fromLocalFile(“本地视频路径”)));

MC_player->setVideoOutput(V_widget);

this->setCentralWidget(V_widget);

    V_widget->show();

    MC_player->play();

connect(MC_player,SIGNAL(mediaStatusChanged(QMediaPlayer::MediaStatus)),this,SLOT(Paly_InitStatus(QMediaPlayer::MediaStatus)));

void Paly_InitStatus(QMediaPlayer::MediaStatus status){

    if(status == QMediaPlayer::EndOfMedia)

    {        MC_player->setPosition(0);

        MC_player->play();
    }

}

当视频播放完成后 QMediaplayer会发送一个信号，捕抓这个信号然后把标志移到初始位置就可以实现重头播放，免去了预加载占用cpu过高的问题。

参考以下可捕抓到很多类似的信号：

Constant	Value	Description
QMediaPlayer::UnknownMediaStatus	0	The status of the media cannot be determined.
QMediaPlayer::NoMedia	1	The is no current media. The player is in the StoppedState.
QMediaPlayer::LoadingMedia	2	The current media is being loaded. The player may be in any state.
QMediaPlayer::LoadedMedia	3	The current media has been loaded. The player is in the StoppedState.
QMediaPlayer::StalledMedia	4	Playback of the current media has stalled due to insufficient buffering or some other temporary interruption. The player is in the PlayingState or PausedState.
QMediaPlayer::BufferingMedia	5	The player is buffering data but has enough data buffered for playback to continue for the immediate future. The player is in the PlayingState or PausedState.
QMediaPlayer::BufferedMedia	6	The player has fully buffered the current media. The player is in the PlayingState or PausedState.
QMediaPlayer::EndOfMedia	7	Playback has reached the end of the current media. The player is in the StoppedState.
QMediaPlayer::InvalidMedia	8	The current media cannot be played. The player is in the StoppedState.

 

 

-------------------------------------------QTimer 问题

再同一个类函数里面构造两个QTimer 时间 如果 设置的开始时间相同 会导致其中一个不能发送timeout() 信号， 我通过设置不一样的时间，来解决了这问题。