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videoitem.cpp Example File
multimedia/videographicsitem/videoitem.cpp

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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;
     }
 }


Copyright © 2010 Nokia Corporation and/or its subsidiary(-ies) Trademarks
Qt 4.6.3