videoplayer.cpp Example File

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  #include "videoplayer.h"

  #include <QtWidgets>
  #include <QVideoSurfaceFormat>
  #include <QGraphicsVideoItem>

  VideoPlayer::VideoPlayer(QWidget *parent)
      : QWidget(parent)
      , mediaPlayer(0, QMediaPlayer::VideoSurface)
      , videoItem(0)
      , playButton(0)
      , positionSlider(0)
  {
      videoItem = new QGraphicsVideoItem;
      videoItem->setSize(QSizeF(640, 480));

      QGraphicsScene *scene = new QGraphicsScene(this);
      QGraphicsView *graphicsView = new QGraphicsView(scene);

      scene->addItem(videoItem);

      QSlider *rotateSlider = new QSlider(Qt::Horizontal);
      rotateSlider->setRange(-180,  180);
      rotateSlider->setValue(0);

      connect(rotateSlider, SIGNAL(valueChanged(int)),
              this, SLOT(rotateVideo(int)));

      QAbstractButton *openButton = new QPushButton(tr("Open..."));
      connect(openButton, SIGNAL(clicked()), this, SLOT(openFile()));

      playButton = new QPushButton;
      playButton->setEnabled(false);
      playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));

      connect(playButton, SIGNAL(clicked()),
              this, SLOT(play()));

      positionSlider = new QSlider(Qt::Horizontal);
      positionSlider->setRange(0, 0);

      connect(positionSlider, SIGNAL(sliderMoved(int)),
              this, SLOT(setPosition(int)));

      QBoxLayout *controlLayout = new QHBoxLayout;
      controlLayout->setMargin(0);
      controlLayout->addWidget(openButton);
      controlLayout->addWidget(playButton);
      controlLayout->addWidget(positionSlider);

      QBoxLayout *layout = new QVBoxLayout;
      layout->addWidget(graphicsView);
      layout->addWidget(rotateSlider);
      layout->addLayout(controlLayout);

      setLayout(layout);

      mediaPlayer.setVideoOutput(videoItem);
      connect(&mediaPlayer, SIGNAL(stateChanged(QMediaPlayer::State)),
              this, SLOT(mediaStateChanged(QMediaPlayer::State)));
      connect(&mediaPlayer, SIGNAL(positionChanged(qint64)), this, SLOT(positionChanged(qint64)));
      connect(&mediaPlayer, SIGNAL(durationChanged(qint64)), this, SLOT(durationChanged(qint64)));
  }

  VideoPlayer::~VideoPlayer()
  {
  }

  void VideoPlayer::openFile()
  {
      QString fileName = QFileDialog::getOpenFileName(this, tr("Open Movie"),QDir::homePath());

      if (!fileName.isEmpty()) {
          mediaPlayer.setMedia(QUrl::fromLocalFile(fileName));

          playButton->setEnabled(true);
      }
  }

  void VideoPlayer::play()
  {
      switch(mediaPlayer.state()) {
      case QMediaPlayer::PlayingState:
          mediaPlayer.pause();
          break;
      default:
          mediaPlayer.play();
          break;
      }
  }

  void VideoPlayer::mediaStateChanged(QMediaPlayer::State state)
  {
      switch(state) {
      case QMediaPlayer::PlayingState:
          playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
          break;
      default:
          playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
          break;
      }
  }

  void VideoPlayer::positionChanged(qint64 position)
  {
      positionSlider->setValue(position);
  }

  void VideoPlayer::durationChanged(qint64 duration)
  {
      positionSlider->setRange(0, duration);
  }

  void VideoPlayer::setPosition(int position)
  {
      mediaPlayer.setPosition(position);
  }

  void VideoPlayer::rotateVideo(int angle)
  {
      //rotate around the center of video element
      qreal x = videoItem->boundingRect().width() / 2.0;
      qreal y = videoItem->boundingRect().height() / 2.0;
      videoItem->setTransform(QTransform().translate(x, y).rotate(angle).translate(-x, -y));
  }