Qt 5.9 | Qt Multimedia | Video Graphics Item Example | videoplayer.cpp Example File

Qt 5.9.9 Reference Documentation

# videoplayer.cpp Example File

multimediawidgets/videographicsitem/videoplayer.cpp

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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)
      {
          const QRect screenGeometry = QApplication::desktop()->screenGeometry(this);
          videoItem = new QGraphicsVideoItem;
          videoItem->setSize(QSizeF(screenGeometry.width() / 3, screenGeometry.height() / 2));

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

          scene->addItem(videoItem);

          QSlider *rotateSlider = new QSlider(Qt::Horizontal);
          rotateSlider->setToolTip(tr("Rotate Video"));
          rotateSlider->setRange(-180,  180);
          rotateSlider->setValue(0);

          connect(rotateSlider, &QAbstractSlider::valueChanged,
                  this, &VideoPlayer::rotateVideo);

          QAbstractButton *openButton = new QPushButton(tr("Open..."));
          connect(openButton, &QAbstractButton::clicked, this, &VideoPlayer::openFile);

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

          connect(playButton, &QAbstractButton::clicked, this, &VideoPlayer::play);

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

          connect(positionSlider, &QAbstractSlider::sliderMoved,
                  this, &VideoPlayer::setPosition);

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

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

          mediaPlayer.setVideoOutput(videoItem);
          connect(&mediaPlayer, &QMediaPlayer::stateChanged,
                  this, &VideoPlayer::mediaStateChanged);
          connect(&mediaPlayer, &QMediaPlayer::positionChanged, this, &VideoPlayer::positionChanged);
          connect(&mediaPlayer, &QMediaPlayer::durationChanged, this, &VideoPlayer::durationChanged);
      }

      VideoPlayer::~VideoPlayer()
      {
      }

      QSize VideoPlayer::sizeHint() const
      {
          return (videoItem->size() * qreal(3) / qreal(2)).toSize();
      }

      bool VideoPlayer::isPlayerAvailable() const
      {
          return mediaPlayer.isAvailable();
      }

      void VideoPlayer::openFile()
      {
          QFileDialog fileDialog(this);
          fileDialog.setAcceptMode(QFileDialog::AcceptOpen);
          fileDialog.setWindowTitle(tr("Open Movie"));
          const QStringList supportedMimeTypes = mediaPlayer.supportedMimeTypes();
          if (!supportedMimeTypes.isEmpty())
              fileDialog.setMimeTypeFilters(supportedMimeTypes);
          fileDialog.setDirectory(QStandardPaths::standardLocations(QStandardPaths::MoviesLocation).value(0, QDir::homePath()));
          if (fileDialog.exec() == QDialog::Accepted)
              load(fileDialog.selectedUrls().constFirst());
      }

      void VideoPlayer::load(const QUrl &url)
      {
          mediaPlayer.setMedia(url);
          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));
      }