Qt Reference Documentation

# videoitem.cpp Example File

multimedia/videographicsitem/videoitem.cpp

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     ** This file is part of the examples of the Qt Toolkit.
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     #include "videoitem.h"

     #include <QtMultimedia>

     VideoItem::VideoItem(QGraphicsItem *parent)
         : QGraphicsItem(parent)
         , imageFormat(QImage::Format_Invalid)
         , framePainted(false)
     {
     }

     VideoItem::~VideoItem()
     {
     }

     QRectF VideoItem::boundingRect() const
     {
         return QRectF(QPointF(0,0), surfaceFormat().sizeHint());
     }

     void VideoItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
     {
         Q_UNUSED(option);
         Q_UNUSED(widget);

         if (currentFrame.map(QAbstractVideoBuffer::ReadOnly)) {
             const QTransform oldTransform = painter->transform();

             if (surfaceFormat().scanLineDirection() == QVideoSurfaceFormat::BottomToTop) {
                painter->scale(1, -1);
                painter->translate(0, -boundingRect().height());
             }

             painter->drawImage(boundingRect(), QImage(
                     currentFrame.bits(),
                     imageSize.width(),
                     imageSize.height(),
                     imageFormat));

             painter->setTransform(oldTransform);

             framePainted = true;

             currentFrame.unmap();
         }
     }

     QList<QVideoFrame::PixelFormat> VideoItem::supportedPixelFormats(
             QAbstractVideoBuffer::HandleType handleType) const
     {
         if (handleType == QAbstractVideoBuffer::NoHandle) {
             return QList<QVideoFrame::PixelFormat>()
                     << QVideoFrame::Format_RGB32
                     << QVideoFrame::Format_ARGB32
                     << QVideoFrame::Format_ARGB32_Premultiplied
                     << QVideoFrame::Format_RGB565
                     << QVideoFrame::Format_RGB555;
         } else {
             return QList<QVideoFrame::PixelFormat>();
         }
     }

     bool VideoItem::start(const QVideoSurfaceFormat &format)
     {
         if (isFormatSupported(format)) {
             imageFormat = QVideoFrame::imageFormatFromPixelFormat(format.pixelFormat());
             imageSize = format.frameSize();
             framePainted = true;

             QAbstractVideoSurface::start(format);

             prepareGeometryChange();

             return true;
         } else {
             return false;
         }
     }

     void VideoItem::stop()
     {
         currentFrame = QVideoFrame();
         framePainted = false;

         QAbstractVideoSurface::stop();
     }

     bool VideoItem::present(const QVideoFrame &frame)
     {
         if (!framePainted) {
             if (!QAbstractVideoSurface::isActive())
                 setError(StoppedError);

             return false;
         } else {
             currentFrame = frame;
             framePainted = false;

             update();

             return true;
         }
     }