videoplayer.cpp Example File

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#include "videoplayer.h"
#include "videowidget.h"
#include <QtMultimedia>
VideoPlayer::VideoPlayer(QWidget *parent)
    : QWidget(parent)
    , surface(0)
    , playButton(0)
    , positionSlider(0)
{
    connect(&movie, SIGNAL(stateChanged(QMovie::MovieState)),
            this, SLOT(movieStateChanged(QMovie::MovieState)));
    connect(&movie, SIGNAL(frameChanged(int)),
            this, SLOT(frameChanged(int)));
    VideoWidget *videoWidget = new VideoWidget;
    surface = videoWidget->videoSurface();
    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)));
    connect(&movie, SIGNAL(frameChanged(int)),
            positionSlider, SLOT(setValue(int)));
    QBoxLayout *controlLayout = new QHBoxLayout;
    controlLayout->setMargin(0);
    controlLayout->addWidget(openButton);
    controlLayout->addWidget(playButton);
    controlLayout->addWidget(positionSlider);
    QBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(videoWidget);
    layout->addLayout(controlLayout);
    setLayout(layout);
}
VideoPlayer::~VideoPlayer()
{
}
void VideoPlayer::openFile()
{
    QStringList supportedFormats;
    foreach (QString fmt, QMovie::supportedFormats())
        supportedFormats << fmt;
    foreach (QString fmt, QImageReader::supportedImageFormats())
        supportedFormats << fmt;
    QString filter = "Images (";
    foreach ( QString fmt, supportedFormats) {
        filter.append(QString("*.%1 ").arg(fmt));
    }
    filter.append(")");
    QString fileName = QFileDialog::getOpenFileName(this, tr("Open Movie"),
            QDir::homePath(), filter);
    if (!fileName.isEmpty()) {
        surface->stop();
        movie.setFileName(fileName);
        playButton->setEnabled(true);
        positionSlider->setMaximum(movie.frameCount());
        movie.jumpToFrame(0);
    }
}
void VideoPlayer::play()
{
    switch(movie.state()) {
    case QMovie::NotRunning:
        movie.start();
        break;
    case QMovie::Paused:
        movie.setPaused(false);
        break;
    case QMovie::Running:
        movie.setPaused(true);
        break;
    }
}
void VideoPlayer::movieStateChanged(QMovie::MovieState state)
{
    switch(state) {
    case QMovie::NotRunning:
    case QMovie::Paused:
        playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
        break;
    case QMovie::Running:
        playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
        break;
    }
}
void VideoPlayer::frameChanged(int frame)
{
    if (!presentImage(movie.currentImage())) {
        movie.stop();
        playButton->setEnabled(false);
        positionSlider->setMaximum(0);
    } else {
        positionSlider->setValue(frame);
    }
}
void VideoPlayer::setPosition(int frame)
{
    movie.jumpToFrame(frame);
}
bool VideoPlayer::presentImage(const QImage &image)
{
    QVideoFrame frame(image);
    if (!frame.isValid())
        return false;
    QVideoSurfaceFormat currentFormat = surface->surfaceFormat();
    if (frame.pixelFormat() != currentFormat.pixelFormat()
            || frame.size() != currentFormat.frameSize()) {
        QVideoSurfaceFormat format(frame.size(), frame.pixelFormat());
        if (!surface->start(format))
            return false;
    }
    if (!surface->present(frame)) {
        surface->stop();
        return false;
    } else {
        return true;
    }
}