QVideoWidget does not display anything

I tested your example and it does not even try to run the file, by looking at the example it sent from the site it looks like this:

playlist = new QMediaPlaylist(player);

It seems that there are some errors in the documentation, QMediaPlaylist does not have the parameter to receive QMediaPlayer , but a QObject , that is, it should only be to define parent , create the player, it seems like an error of the tutorial of them, see how is the class QMediaPlaylist :

QMediaPlaylist(QObject *parent = 0);
virtual ~QMediaPlaylist();

Another thing I noticed is that by adding "media items" you have used QUrl , but I believe that the correct one is QMediaContent for both remote and local files.

Another thing I noticed is that it is necessary to set the minimum size of QVideoWidget , otherwise it will render as 0 , you can also add it within a QWidget or QMainWindow

@LuizViera also looked at a detail, QUrl does not add file:/// to local files, so you need to use QUrl::fromLocalFile .

The code for basic operation would look like this:

QMediaContent videoItem1(QUrl::fromLocalFile("C:/Users/Guilherme/exemplo.mp4"));
playlist->addMedia(videoItem1);

I believe the correct path is this:

player = new QMediaPlayer;

playlist = new QMediaPlaylist();

//Define o playlist no player
player->setPlaylist(playlist);

//item index 0
playlist->addMedia(QMediaContent(QUrl::fromLocalFile("http://www.sample-videos.com/video/mp4/720/big_buck_bunny_720p_1mb.mp4")));

//item index 1
playlist->addMedia(QMediaContent(QUrl::fromLocalFile("http://techslides.com/demos/sample-videos/small.mp4")));

videoWidget = new QVideoWidget;
player->setVideoOutput(videoWidget);

videoWidget->show();

//Define o minimo do tamanho do video
videoWidget->setMinimumSize(100, 100);

playlist->setCurrentIndex(1);
player->play();

  

Just a note: if a message similar to this appears in the Qt log (under Windows):

DirectShowPlayerService::doRender: Unresolved error code 80040266

     

This is due to the lack of CODECs for x86 / 32bit version (depending on your version)

One thing you can add is the events to check other errors (change [SUA CLASSE] to the class where you will organize the main, perhaps the custom window of a player):

• Your file .h usually:

  public slots:
      void statusChanged(QMediaPlayer::MediaStatus status);
      void displayErrorMessage();
  

• Your file .cpp usually:

  void [SUA CLASSE]::statusChanged(QMediaPlayer::MediaStatus status)
  {
      switch (status) {
      case QMediaPlayer::UnknownMediaStatus:
      case QMediaPlayer::NoMedia:
      case QMediaPlayer::LoadedMedia:
      case QMediaPlayer::BufferingMedia:
      case QMediaPlayer::BufferedMedia:
          qDebug() << status;
          break;
      case QMediaPlayer::LoadingMedia:
          qDebug() << "Loading...";
          break;
      case QMediaPlayer::StalledMedia:
          qDebug() << "Media Stalled";
          break;
      case QMediaPlayer::EndOfMedia:
          qDebug() << "Media end";
          break;
      case QMediaPlayer::InvalidMedia:
          displayErrorMessage();
          break;
      }
  }
  
  void [SUA CLASSE]::displayErrorMessage()
  {
      qDebug() << player->errorString();
  }
  

• And add the signs to SLOTS :

  connect(player, SIGNAL(error(QMediaPlayer::Error)), this, SLOT(displayErrorMessage()));
  connect(player, SIGNAL(mediaStatusChanged(QMediaPlayer::MediaStatus)), this, SLOT(statusChanged(QMediaPlayer::MediaStatus)));
  

There is also a complete example in the documentation for studying:

• link

A test run:

linkofthevideo: link