videoplayer.cpp Example File

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 #include "videoplayer.h"

 #include <QtWidgets>
 #include <QGraphicsVideoItem>

 VideoPlayer::VideoPlayer(QWidget *parent)
     : QWidget(parent)
 {
     m_mediaPlayer = new QMediaPlayer(this, QMediaPlayer::VideoSurface);
     const QRect screenGeometry = QApplication::desktop()->screenGeometry(this);
     m_videoItem = new QGraphicsVideoItem;
     m_videoItem->setSize(QSizeF(screenGeometry.width() / 3, screenGeometry.height() / 2));

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

     scene->addItem(m_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);

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

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

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

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

     QBoxLayout *controlLayout = new QHBoxLayout;
     controlLayout->setMargin(0);
     controlLayout->addWidget(openButton);
     controlLayout->addWidget(m_playButton);
     controlLayout->addWidget(m_positionSlider);

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

     m_mediaPlayer->setVideoOutput(m_videoItem);
     connect(m_mediaPlayer, &QMediaPlayer::stateChanged,
             this, &VideoPlayer::mediaStateChanged);
     connect(m_mediaPlayer, &QMediaPlayer::positionChanged, this, &VideoPlayer::positionChanged);
     connect(m_mediaPlayer, &QMediaPlayer::durationChanged, this, &VideoPlayer::durationChanged);
 }

 VideoPlayer::~VideoPlayer()
 {
 }

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

 bool VideoPlayer::isPlayerAvailable() const
 {
     return m_mediaPlayer->isAvailable();
 }

 void VideoPlayer::openFile()
 {
     QFileDialog fileDialog(this);
     fileDialog.setAcceptMode(QFileDialog::AcceptOpen);
     fileDialog.setWindowTitle(tr("Open Movie"));
     const QStringList supportedMimeTypes = m_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)
 {
     m_mediaPlayer->setMedia(url);
     m_playButton->setEnabled(true);
 }

 void VideoPlayer::play()
 {
     switch (m_mediaPlayer->state()) {
     case QMediaPlayer::PlayingState:
         m_mediaPlayer->pause();
         break;
     default:
         m_mediaPlayer->play();
         break;
     }
 }

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

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

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

 void VideoPlayer::setPosition(int position)
 {
     m_mediaPlayer->setPosition(position);
 }

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